Glossary  

Abnormal: Not normal; Deviating from the usual structure, position, condition, or behaviour. In referring to a growth, abnormal may mean that it is cancerous or pre malignant (likely to become cancer).

Acetretin: A vitamin A derivative taken by mouth usually used to treat moderate to severe psoriasis. It is sold under the trade name Neotigason.

Active ingredient: The ingredient in a topical or oral medicine that is known or expected to have a thera­peutic effect.

Acupuncture: A traditional Chinese medicine that involves inserting needles at specific points on the body to help treat pain and illness. It is one of the alternative therapies sometimes used to treat psoriasis.

Acute: Refers to immediate or short­ term changes, usually within hours or days. Of abrupt onset, in reference to a disease. Acute often also connotes an illness that is of short duration, rapidly progressive, and in need of urgent care.

Adalimumab: A biologic therapy that works by inhibiting TNF -a. It is currently being used and under study for the treatment of moderate to se­vere psoriasis. It is sold under the trade name Humira.

Adverse event: An unwanted change or effect caused, or thought to be caused, by a medication. This is also known as a "side effect."

Alefacept: A biologic therapy that works by inhibiting and eliminating T cells that is usually used to treat moderate to severe psoriasis. It is sold un­der the trade name Amevive.

Aloe: A moisturizer, usually in gel form, that is derived from the aloe plant.

Alternative therapy: Also called complementary therapy or alternative medicine. An um­brella term for non prescription med­ications such as herbs and supple­ments, and non traditional therapies such as acupuncture, massage, or stress reduction.

Angiogenesis: Formation of new blood vessels in the body; thought to be involved in the development of psoriasis lesions.

Anthralin: A derivative of tar that is used to treat psoriasis. It decreases skin inflammation, but can stain skin and clothing. It is also called dithranol. It is often used in combination with UV light.

Antibody: A protein produced by the immune system cells that binds to antigens so other elements of the immune system can attack and destroy or remove the antigen.

Antigen: A large molecule or small organism, such as the strep throat bacterium, whose entry into the body provokes an immune-system response.

Antipsoriatic: Medicine used for treating psoriasis.

Antisense: Man-made DNA designed to bind to natural RNA within cells to prevent the production of a protein involved in psoriasis.

Apoptosis: Orderly cell death that is programmed by the body.

Arachidonic acid: A fatty acid found in high concentrations in the skin of people with psoriasis, suggesting that it could be one of the factors that contribute to inflammation and cell proliferation.

Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis.

Arthritis mutilans: Joint inflamma­tion (arthritis) that causes permanent and sometimes mutilating joint changes.

Atrophy: Thinning of the skin that can be an unwanted side effect of top­ical steroid use. Atrophy decreases the thickness and strength of the affected skin.

Atypical presentation: A situation in which a disease arises and appears dif­ferent than normal (in a different place or with a different appearance, for ex­ample), usually necessitating further tests for an accurate diagnosis.

Auspitz Sign: A skin phenomenon often seen in psoriasis, where pin­point spots of blood appear when a scale is lifted off of the skin.

Autoantibodies: Abnormal antibodies produced against the body's own tissues.

Autoimmune disease: A disease in which autoantibodies or lymphocytes attack other molecules, cells, or tissues within the body; the body launches an immune response against its own tissue. Psoriasis is widely believed to be an autoimmune disease, as is psoriatic arthritis.

Basal Cell Carcinoma (BCC): The most common form of skin cancer often appears as a small, shiny, raised bump on sun-exposed skin. BCC is commonly associated with overexposure of the skin to ultraviolet light, and/or other contributing factors.

B cell: A type of white blood cell involved in the production of antibodies. These cells are produced in bone marrow.

Basal cell layer: The lowest layer of the epidermis, where skin cells develop.

Base: The type of substance that a topical medicine may be formulated in, e.g. an ointment, cream, lotion, or foam.

Bath PUVA: This is a type of PUVA ther­apy where psoralen is washed over the skin in a bath, rather than taken by mouth, before UVA therapy is given.

Beta-blockers: Medications that are commonly prescribed for lowering blood pressure, relieving angina, or treating congestive heart failure. These drugs are thought to trigger or aggravate psoriasis in some people.

Bioavailability: The degree to which a drug or other substance becomes available to the target body tissue after administration.

Biofeedback: A relaxation technique in which people are taught to control some body functions such as blood pressure or heart rate, which are usually considered involuntary.

Biologic therapies: Medical preparations derived from living organisms. In psoriasis, this category of pharmaceuticals may target the immune system. They are also called biologics or biologicals.

Biopsy: The removal of a sample of tissue for purposes of diagnosis. (Many definitions of "biopsy" stipulate that the sample of tissue is removed for examination under a microscope. This may or may not be the case. The diagnosis may be achieved by other means such as by analysis of chromosomes or genes.)

Biotechnology: A set of techniques, such as those used to make DNA in laboratories, developed through basic research and that are now used by companies to make new drugs.

Bitumen: A form of natural tar which may be used to treat psoriasis.

Blood: The familiar red fluid in the body that contains white and red blood cells, platelets, proteins, and other elements. The blood is transported throughout the body by the circulatory system. Blood functions in two directions: arterial and venous. Arterial blood is the means by which oxygen and nutrients are transported to tissues while venous blood is the means by which carbon dioxide and metabolic by-products are transported to the lungs and kidneys, respectively, for removal from the body.

Body surface area (BSA): The area of skin on a person, measured in square feet or square meters. Usually used as a percentage to describe the propor­tion of the body's skin that is affected or covered.

Broadband light therapy: The type of light therapy available at many dermatologists' offices for the treatment of psoriasis. As the name suggests, it offers a broad range of UVB light (280 nm to 315 nm). Another form of UVB therapy also available from dermatologists emits a narrower band in the upper range of UVB light (311 nm to 313 nm), which has been proven more effective than broadband.

Burn: Damage to the skin or other body parts caused by extreme heat, flame, contact with heated objects, or chemicals. Burn depth is generally categorized as first, second, or third degree. The treatment of burns depends on the depth, area, and location of the burn, as well as additional factors, such as material that may be burned onto or into the skin. Treatment options range from simply applying a cold pack to emergency treatment to skin grafts.

Calcipotriene, calcipotriol: A topi­cally applied Vitamin D3 derivative used to treat psoriasis. It is sold under the trade name Dovonex.

Candidate genes: Genes that are potentially linked to a disease.

Cataract: Clouding of the lens of the eye, which leads to vision loss. Patients receiving PUVA treatment must be especially careful to protect their eyes during and immediately after treatments.

Cell: The basic structural and func­tional unit in the human body; the building blocks of each organ and tissue. A cell contains all of the genetic information it takes to make a human being. The cell nucleus contains 23 pairs of chromosomes (one half of each pair is inherited from each parent).

Chimera: A molecule that contains genetic material from two species, e.g., mouse and human.

Chromosome: A molecule of DNA found in the nucleus of every cell, chromosomes contain the cell's ge­netic information. Humans normally have 46 chromosomes.
Each chromosome contains hundreds to thousands of individual genes, which give people their distinct characteristics. Each human has about 30,000 to 35,000 genes in total. Genetic information is encoded in long strands of a chemical called deoxyribonucleic acid (DNA), which is shaped in two connected strands that look like a twisted ladder (the shape is called a "double helix").

Chronic: This important term in medicine comes from the Greek "chronos", time and means lasting a long time.

Cirrhosis: A disease characterized by the build up of scar tissue and nodules in the liver that interfere with its function.

Climatotherapy: Treatment of pso­riasis by going to a climate that is likely to improve psoriasis due to the sunlight exposure and sometimes humidity.

Clinical diagnosis: Diagnosis based on clinical information, such as ap­pearance and history, as opposed to being based on laboratory tests.

Clinical trial: A formally designed, officially reviewed scientific study of diagnosis, treatment, interven­tion, or prevention of a particular disease.

Clobetasol propionate: Corticosteroid applied topically for relief of inflammation and itching.

Coal tar: A brown or black material, liq­uid or semi-solid in consistency, de­rived from coal, petroleum, wood, or other organic material. Used on the skin, it has immunosuppressant qualities and has long been used to treat psoriasis.

Condition: The term "condition" has a number of biomedical meanings including the following:

1. An unhealthy state, such as in "this is a progressive condition."
2. A state of fitness, such as "getting into condition."
3. Something that is essential to the occurrence of something else; essentially a "precondition."
4. As a verb: to cause a change in something so that a response that was previously associated with a certain stimulus becomes associated with another stimulus; to condition a person, as in behavioural conditioning.

Corticosteroid: A synthetic hormone that is similar to any of the steroid hormones made by the cortex (outer layer) of the adrenal gland. Cortisol is a corticosteroid. It is available in pill, topical, and injectable forms.

Cortisone: An adrenocorticoid hormone, a naturally occurring hormone made by and secreted by the adrenal cortex, the outer part (the cortex) of the adrenal gland.

Crohn's Disease: A chronic illness that causes irritation in the digestive tract. It occurs most commonly in the ileum (lower small intestine) or in the colon (large intestine). It is a form of inflammatory bowel disease.

Crude coal tar: Under very high tem­peratures, coal can be destructively distilled to crude coal tar. When ap­plied to skin, coal tar has antibacter­ial, anti-itching, and photosensitizing properties.

Cyclosporine: A drug derived from a fungus that inhibits the body's im­mune responses. It is a common drug for patients with organ transplants and is also used in many autoimmune diseases.

Combination therapy: Combining two or more treatments to improve effectiveness and in some cases to minimize side effects.

Complication: A problem that oc­curs after using a medication or ther­apy. It is also known as a side effect.

Complimentary therapy: An umbrella term, sometimes used interchangeably with "alternative therapy," that de­scribes non prescription medicines, sup­plements, and disease therapies.

Compounding: Mixing two or more different medications into a topical cream or ointment.

Corticosteroid: An umbrella term for different steroid compounds. These are sometimes simply called steroids.

Cream: An emulsion (mixture) of oil and water for the skin that is used to impart moisture. A cream is usually thicker than a lotion. A word with many meanings that, in medicine and pharmacy, refers to a water-soluble preparation applied to the skin. An ointment differs from a cream in that it has an oil base.

Cutaneous: Pertaining to the skin.

Cytokine: Proteins used by the immune system to communicate messages between cells; in psoriasis, cytokines carry messages that promote inflammation and the overly rapid development of skin cells.

Dead Sea: An inland body of water in Israel that has been known for centuries for its beneficial effects on disease, including psoriasis.

Denial: A defence mechanism in which the existence of unpleasant realities is kept out of conscious awareness.

Deoxyribonucleic acid (DNA): Fundamental hereditary material of all living organisms; stored primarily in the cell's nucleus.

Depression: An illness that involves the body, mood, and thoughts that affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. A depressive disorder is not the same as a passing blue mood. It is not a sign of personal weakness or a condition that can be wished away. People with a depressive disease cannot merely "pull themselves together" and get better. Without treatment, symptoms can last for weeks, months, or years. Appropriate treatment, however, can help most people with depression.

Dermatitis: Inflammation of the skin that may result in redness or itching.

Dermatologist: A physician special­izing in the diagnosis and treatment of skin disease.

Dermatopathologist: A physician specializing in diagnosing skin dis­ease by its appearance under the microscope.

Dermis: The layer of skin just under­neath the epidermis that contains the skin's nerve endings, blood vessels, hair follicles, sweat glands, and im­mune cells.

Desensitization: The process of rendering an individual insensitive to physical or emotional stimuli.

Diagnosis: 1. The nature of a disease; the identification of an illness. 2. A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3. The identification of any problem. The diagnosis was a plugged IV.

Disability: A physical or psychological impairment that affects a person's ability to perform everyday functions.

Disease: Illness or sickness often characterized by typical patient problems (symptoms) and physical findings (signs). Disruption sequence: The events that occur when a foetus that is developing normally is subjected to a destructive agent such as the rubella (German measles) virus.

Disease-modifying Antirheumatic Drugs (DMARDs): A class of medication that has the potential to reduce or prevent joint damage, preserve joint function, and maintain productivity of the patient.

Distal interphalangeal joints: The small joints of the fingers closest to the nails.

Dithranol: A derivative of tar that is used to treat psoriasis. It decreases skin inflammation, but can stain skin and clothing. It is also called anthralin.

DNA: Deoxyribonucleic acid, fundamental hereditary material of all living organisms; stored primarily in the cell's nucleus.

Dovonex^® (calcipotriene): A synthetic form of vitamin D₃, used topically to treat plaque psoriasis.

Dry skin: Abnormally dry skin. It can be caused by a dry climate, winter weather, deficiency of vitamin A, systemic illness, overexposure to sunlight, or medication. The skin loses moisture. It may crack and peel. Or it may become irritated, inflamed, and itchy. Bathing frequently, especially with soaps, can contribute to dry skin.

Eczema: An inflammatory disease of the skin, characterized by oozing, crusting, and/or scaling. There is also an eczema-type psoriasis, which is most common on the hands and feet and is characterized by itchiness, inflammation, and painful cracks in the skin.

Edema: A build up of fluid in cells or tissues that produces swelling, often in the lower legs and feet.

Efalizumab: A biologic therapy that works by inhibiting T cells that is usually used to treat moderate to se­vere psoriasis. It is sold under the trade name Raptiva.

Eligibility criteria: In a clinical trial, the criteria that it patient needs to meet in order to participate. Exam­ples include being over age 18, or not planning to become pregnant during the study.

Emollient: An agent that holds moisture in the skin and by doing so softens or soothes it.

Empathy: The ability to recognize and share the emotions of another person.

Endorphins: A group of proteins released by the brain, often in response to stress or exercise, that reduce the perception of pain.

Endotoxin: A substance found in the cell walls of certain bacteria that can be extremely toxic to people, producing fever, shock, and even death.

Epidermis: The outermost layer of skin. It is the nonvascular (without blood vessels) layer that covers and protects the dermis.

Eruptions: Lesions on the skin that are usually red, raised and easily visible.

Erythema: A medical term referring to redness of the skin due to blood vessel dilation.

Erythroderma: Full-body redness of the skin due to any cause, including psoriasis.

Erythrodermic psoriasis: This is a particularly inflammatory form of psoriasis that often affects most of the body surface. It is the least common form of psoriasis and most commonly appears on people who have unstable plaque psoriasis, where lesions are not clearly defined. The erythrodermic form of psoriasis is characterized by periodic, widespread, fiery redness of the skin. The erythema (reddening) and exfoliation (shedding) of the skin are often accompanied by severe itching and pain. Swelling may also develop. It is also termed exfoliative psoriasis.

Etanercept: A biologic therapy that works by inhibiting TNF -ex, currently usually used to treat moderate to severe psoriasis. It is sold under the trade name Enbrel.

Excimer laser: A laser used by der­matologists that works at 311 nm wavelength, similar to the wavelength of UVB. It has been shown to be ef­fective for treating psoriasis in local areas, and is given in a dermatologist's office.

Exfoliation: Peeling and sloughing off of the skin's tissue cells.

Exfoliative psoriasis: This is a particularly inflammatory form of psoriasis that often affects most of the body surface. It is the least common form of psoriasis and most commonly appears on people who have unstable plaque psoriasis, where lesions are not clearly defined. The erythrodermic form of psoriasis is characterized by periodic, widespread, fiery redness of the skin. The erythema (reddening) and exfoliation (shedding) of the skin are often accompanied by severe itching and pain. Swelling may also develop. It is also termed erythrodemic psoriasis.

Exotoxin: A poison released from a living micro organism.

Fish oils: Oils derived from fish that are rich in omega-3, a polyunsaturated fat often missing from many people's diets.

Flare-up: A worsening of a disease.

Flexural psoriasis (also known as inverse psoriasis): Psoriasis that occurs in the skin folds, such as the underarm or groin area, that can cause significant discomfort when one part of the skin rubs against another. When this occurs in the genital area, it can cause difficulty with sexual activities.

Foam: An inert base or vehicle made of alcohol and or water in which an active ingredient such as a topical steroid can be mixed. A foam may ap­pear similar in consistency to hair mousse, but is used on the skin.

Focus meditation: Engaging in extended thought or contemplation; a method for reducing stress.

Folklore: A body of popular but unsubstantiated or false beliefs.

Food and Drug Administration (FDA): The USA federal organization dedicated to protecting the safety of the food and drug supply for the USA, trickling down to the rest of the world.

Food supplements: Substances added to the diet with supposed health benefits.

Fusion protein: Parts of fully human amino acid sequences fused together into one protein; can be used to block the interaction between two cells.

Gastroenterologist: A physician who specializes in diseases of the digestive tract, gall bladder, and liver.

Gene: The segment of DNA on a chromosome that contains the infor­mation necessary to make a protein. A gene is the unit of biological inher­itance.

Genes and base pairs: Genes are arranged like beads on a string-they are short sections of DNA that hold the "recipe" for a specific protein or molecule. The recipe is spelled out by the arrangement of four chemicals that connect the strands of DNA in pairs ("base pairs").

Gene therapy: The injection of healthy genes into the bloodstream for the purpose of curing a hereditary disease.

Genetics: The study of how diseases, conditions, and traits are inherited.

Goeckerman Regimen: A treat­ment regimen combining topical tar and light therapy usually per­formed at designated psoriasis treat­ment centres.

Gold: This is a precious metal that can also be in drug form: either oral or injectable. It is sometimes used in the treatment of psoriatic arthritis. Careful monitoring is required.

Guided imagery: A way to reduce stress by focusing on suggested mental visualizations.

Guttate psoriasis: A type of psoriasis characterized by drop-like lesions on the trunk, limbs, and scalp. Symptoms may be triggered by viral respiratory infections or certain bacterial (streptococcal) infections.

Hand/foot therapy: A treatment for psoriasis that uses specialized ultraviolet light units on the palms of the hands and soles of the feet.

Heliotherapy: Treatment of psoriasis by going to a climate that is likely to improve psoriasis due to sunlight exposure.

Herbalism: The practice of using medicinal herbs to treat disease.

Heredity: The transmission of traits from one generation to the next.

Holistic medicine: Natural healing directed at an individual's physical, spiritual, and emotional needs.

Human leukocyte antigen (HLA) system: Proteins located on the sur­face of white blood cells that play an important role in our body's immune response to foreign substances.

Homeopathy: A medical practice that activates one's own healing process by using tiny doses of substances in order to stimulate the body's natural defences.

Hyperkeratinization: Skin thickened in the outermost layer, caused by the over activity of keratinocytes in psoriasis.

Home phototherapy: The therapeutic use of an ultraviolet light source in the home, as prescribed by a doctor.

Hormone: A chemical substance that the body produces to regulate the activity of organs(s) or tissue(s).

Hydration: A gain of water or moisture.

Hydroxyurea: One of the older anti-cancer drugs that is sometimes used in the treatment of psoriasis. When combined with acitretin, it can become more effective. Either in combination or alone, its use requires careful blood monitoring.

Hyperplasia: Abnormal increases in the number of cells in skin tissue.

Idiosyncrasy: In terms of medications: an individual's unique reaction to a particular drug.

IFPA: The International Federation of Psoriasis Associations, an international organisation based in Sweden that acts as an umbrella body for al national psoriasis associations worldwide.

IL-2 fusion toxins: Toxins that selectively bind to activated T cells and destroy them.

Immune: Protected against infection. The Latin immunis means free, exempt.

Immune deficiency: The body's inability to maintain an intact immune system.

Immune response: The reactions of the immune system to foreign substances.

Immune system: The immune sys­tem is a collection of cells and pro­teins that works to protect the body from potentially harmful or infectious micro organisms such as bacteria, viruses, and fungi. The immune sys­tem plays a role in the control of can­cer and other diseases, but can also cause autoimmune diseases, allergies, and rejection of transplanted organs.

Immunologic: Pertaining to the immune system.

Immunomodulator: A medication that modifies how the immune sys­tem functions or responds.

Immunosuppressive: A drug that reduces the body's natural immunity.

Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment there from.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person.

Inflammation: A basic way in which the body reacts to infection , irritation or other injury, the key feature being redness, warmth, swelling and pain . Inflammation is now recognized as a type of non-specific immune response.

Inheritance: Not something that is contained in a will, but rather a gene, chromosome or genome that is transmitted from parent to child.

Informed consent: A document that outlines a person's participation, in a clinical trial. Each participant in a clin­ical trial must sign a con­sent form that explains the purpose of the trial, the results expected, how the trial works, potential risks, and a list of other treatments that are available.

Institutional Review Board (IRB): Institutional Review Boards, or IRBs, review research studies that involve human participants. They ensure the ethical and safe treatment of study participants.

Interferons: Proteins formed when cells are exposed to a virus or another particle of nucleic acid. Interferons can be used therapeutically for certain diseases such as psoriasis.

Intergluteal: Between the buttocks

Interleukin: Cytokines that stimulate the growth and maturation of cells of the immune system.

Intertriginous psoriasis: Psoriasis that affects intertriginous areas such as the armpits or the groin. This type of psoriasis can appear different than other types of psoriasis and may be treated differently. This is also known as inverse psoriasis.

Intramuscular: An injection into the muscle layer.

Intravenous: Med­ication or fluid given by injection or infusion into a vein.

Inverse psoriasis: Also called flexural psoriasis, a form of psoriasis found in the armpits, groin, under the breasts and in other flexion creases (skin folds) such as those around the genitals and buttocks. This form of psoriasis appears as smooth, dry areas of skin that are red and inflamed but do not have the scaling associated with plaque psoriasis (the most common type of psoriasis). Inverse psoriasis is more frequent and severe in people who are overweight because it is in the skin folds where it is particularly prone to irritation from rubbing and sweating. This is also called intertriginous psoriasis or flexural psoriasis.

Immunosuppressant: Anything that inhibits or weakens the immune sys­tem. Immunosuppressants can be drugs such as prednisone and cy­closporine, or a disease such as cancer or HIV.

Immunosuppression: Suppression of the natural immune response because immune system defences have been suppressed, damaged, or weakened.

Indication: A symptom, like itching, or condition, like psoriasis, that can be treated through the use of a specific medical treatment or procedure.

Induration: A medical term for thickening of the skin, as sometimes seen in psoriasis.

Infliximab: A biologic therapy that works by inhibiting TNF -a, under study and being used for the treat­ment of moderate to severe psoriasis.

International Federation of Psoriasis Associations (IFPA): An international organisation based in Sweden that acts as an umbrella body for al national psoriasis associations worldwide.

Inverse psoriasis: Psoriasis that af­fects skin folds, interiginous areas, and/or genitals.

Iritis: Inflammation of the eye, some­times as the result of an autoimmune disease. It is also called anterior uveitis.

Itching: An uncomfortable sensation in the skin that feels as if something is crawling on the skin or in the skin and makes the person want to scratch the affected area.

Joint: A joint is the area where two bones are attached for the purpose of motion of body parts. A joint is usually formed of fibrous connective tissue and cartilage. An articulation or an arthrosis is the same as a joint.

Keratin: Any of a family of proteins that form the primary chemical components of the skin, hair, and nails.

Keratinocyte: A type of skin cell; hyper proliferation (accelerated growth) of these cells leads to development of psoriasis lesions.

Keratolysis: A disease in which the outer layer of skin is shed on a regular basis.

Keratolytic: A compound that helps remove dead skin cells from the epi­dermis and breaks down keratin in scale. One example is the group of al­pha hydroxy acids.

Koebner Phenomenon: This phe­nomenon, seen in psoriasis and other skin diseases, occurs when skin trauma initiates new lesions in previ­ously healthy skin. This is also referred to as Koebnerization.

Laser: An acronym for "Light Am­plification by Stimulated Emission of Radiation," a laser is a medical instru­ment that produces a powerful beam of light. It can produce intense heat or cool vaporization when focused at close range, and is often used in medicine.

Latent tuberculosis: Tuberculosis (or TB) is an infectious disease caused by a type of bacteria. The most common target of the disease is the lungs. In some people, the dis­ease may remain quiet without symptoms, but the bacterium is present. This state is referred to as latent TB, and can reactivate if a person starts taking an immunosup­pressive therapy.

LCD: Liquor carbonis detergent, a tar preparation used to treat psoriasis.

Lesion: Patch of skin affected by psoriasis.

Linkage: Identification of genes that may be linked because they reside on the same chromosome.

Lipids: Cholesterol and other fats found in the bloodstream, such as triglycerides.

Liquor carbonis detergens (LCD): Crude coal can be refined with alco­hol extraction to yield liquor carbonis detergens (LCD). This type of tar therapy works like other tar types, to decrease skin inflammation.

Lithium: A substance used in the treatment of bipolar disorder that may possibly trigger or aggravate psoriasis.

Liver: An organ in the upper abdomen that aids in digestion and removes waste products and worn-out cells from the blood. The liver is the largest solid organ in the body. The liver weighs about three and a half pounds (1.6 kilograms). It measures about 8 inches (20 cm) horizontally (across) and 6.5 inches (17 cm) vertically (down) and is 4.5 inches (12 cm) thick.

Liver biopsy: The removal of a small piece of tissue from the liver using a special needle. The tissue is then examined under a microscope for the presence of inflammation or liver damage.

Liver dysfunction: A condition in which the liver does not work normally.

Local effects: Effects of a medica­tion, either beneficial or unwanted, that appear only at the site of ad­ministration. For example, a topical corticosteroid could treat psoriasis locally, or could cause local skin thinning.

Lotion: A water, or water and alcohol ­based topical medication used to treat the skin, sometimes called a "solution."

Lymphocytes: Cells of the body that form the basis of an individual's immune system.

Macerate: To soften by soaking.

Macrophage: Also called an "antigen-presenting cell," macrophages destroy foreign antigens and initiate T cell formation.

Maintenance program: A treatment program that is initiated to keep a disease in remission after an intensive course of therapy.

Malignant melanoma: A potentially fatal form of skin cancer. Psoriasis patients receiving PUVA should be carefully screened for this, even after they've finished their therapy; usually treatable when detected early.

Mapping: Determination of the relative positions of genes on a DNA molecule (chromosome or plasmid) and of the distance, in linkage units or physical units, between them. In psoriasis research, scientists narrow their search for disease-related genes by looking for distinct sequences of base pairs ("markers") that seem to pass through family members in connection ("linked") with a genetic disease. Candidate genes that are linked to the marker can then be tested one by one.

Marker: Gene with a known location on a chromosome; used as a point of reference when doing linkage analysis.

Medical dermatology: The branch of dermatology that treats medical diseases of the skin, such as psoriasis, that may need systemic drug therapy, or skin changes that arise from sys­temic diseases.

Melanocyte: The skin cells that pro­duce melanin (the primary pigment that gives skin its colour), and are found in the basal layer of the epidermis.

Methotrexate: A cytotoxic (cell­ killing) immunosuppressive drug that is used in high doses for the treatment of cancer, and in lower doses for au­toimmune disorders.
Methotrexate is a drug that acts as an antimetabolite and specifically as a folic acid antagonist that inhibits the synthesis of DNA, RNA, and protein.
Methotrexate (MTX) is used to treat diseases associated with abnormally rapid cell growth such as certain tumours and psoriasis. Tumours treated with MTX include acute lymphocytic leukemia (ALL), acute myelocytic leukemia (AML), hydatidiform mole and choriocarcinoma, breast cancer, lung cancer, head and neck cancer, mycosis fungoides, and osteosarcoma.
Aside from psoriasis, methotrexate has also been found helpful in treating autoimmune diseases such as dermatomyositis and rheumatoid arthritis.
Methotrexate, especially in higher doses, can cause adverse reactions. The most frequent reactions include mouth sores, stomach upset, and low white blood counts. Methotrexate can be toxic to the bone marrow and liver.

Mild psoriasis: A condition in which only a few areas of the body have lesions from psoriasis.

Milk thistle: A herbal medicine believed to improve liver function.

Moderate psoriasis: Psoriasis that covers 3% to 10% of the body.

Modified Goeckerman regimen: An outpatient treatment that employs less tar or ointment than the standard Goeckerman regimen. (See Goeckerman regimen.)

Monoclonal antibody (MAb): antibodies created with biotechnology techniques in laboratories. MAbs are highly specific and "recognize" and target only one molecule, such as a receptor, or antigen.

Mucous membranes: The linings of the mouth, nose, vagina, and urethra (inside of the penis). These moist skin areas secrete mucous to keep the sur­faces moist.

Multifactoral: Resulting from multiple factors interacting together.

Nail psoriasis: Psoriasis that affects the fingernails and toenails and involves any of a number of changes to the nail area, including discoloration and the formation of small pits in the nails.

Narrow-band UVB: Narrow-band UVB refers to a specific wavelength of UV radiation, 311 to 313 nm. This range has proven the most beneficial compo­nent of natural sunlight for psoriasis.

National Psoriasis Foundation: A USA, national organization dedicated to helping people with psoriasis.

Naturopathy: A form of therapy based on the belief that all disease is caused by excess toxins in the body.

Neutrophil: The most common type of white blood cell in the blood­stream, it helps defend against bacte­rial infections. When these cells accu­mulate in large areas, pus is formed.

Non-steroidal anti-inflammatories (NSAIDs): Aspirin, ibuprofen (the active ingredient in Motrin or Advil), indomethecin, and some other painkillers have both anti-inflamma­tory and anti-pain properties. These medications are distinct from steroid ­based anti-inflammatories such as prednisone and dexamethasone.

Nutritional supplement: As defined by the FDA, a nutritional supple­ment is a product intended to sup­plement the diet that contains one or more of the following dietary ingre­dients: a vitamin, a mineral, an herb or other botanical, an amino acid, or a dietary substance to supplement the diet by increasing the total daily intake.

Occlusion: Covering, for example, with cotton (i.e., cotton socks or gloves), plastic wrap, or tape.

Off-label prescribing: The common and accepted practice of using a pre­scription medication for a purpose other than the one for which it was approved.

Oil spot: A description of the ap­pearance of small spots (1 to 4 mm) on the nail in psoriasis. These occur when the nail separates from the skin below because of psoriasis in the nail bed.

Ointment: A topical formulation that mixes an active ingredient into a base of solely petrolatum (i.e., Vaseline) with­out any water content. Medications can be mixed into ointments for topical use. Among topical formulas, ointments tend to be the most effective. An ointment has an oil base whereas a cream is water-soluble. (The word ointment comes from the Latin "ungere" meaning anoint with oil).

Oligoarthritis: Inflammation of a few (oligo-) joints (-arthritis)

Onycholysis: A medical term for nail splitting and crumbling, whether from psoriasis or another cause such as a fungus.

Oral: Relating to the mouth.

Oral medication: Medication taken by mouth.

Oral tolerisation: A treatment in which a foreign protein is ingested in an attempt to develop a tolerance to it.

Over-the-counter (OTC): Products (medications, creams, vitamins, sup­plements, etc.) available at the drug­store. These medications can be ef­fective, but are not usually covered by Insurance.

Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia . Pain is mediated by specific nerve fibres that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors.

Paint PUVA: A special type of PUVA where psoralen is "painted" directly onto the skin before exposure to UVA light in the same area.

Palmar-plantar psoriasis: Psoriasis on the hands and feet. This psoriasis may appear different from other types. (It is also called palmoplantar psoriasis.)

Parenterally: Giving a medication in a way other than by mouth, such as by injection or infusion.

PASI Score: A specialized way to measure changes in psoriasis sever­ity used in research studies. It incor­porates psoriasis area and psoriasis activity (redness, thickness, and scale). PASI 75 indicates a 75% improvement in the PASI score, often used to track improvement in stud­ies of new medications. PASI 50 is a 50% improvement in the PASI score.

Pathologist: A doctor who identifies diseases by studying cells and tissues under a microscope.

Pathology report: The formal report of a physician after looking at a skin sample under the microscope. This report is part of a patient's medical record.

Petrolatum: A semi-solid mixture of hydrocarbons that are inert and free of water molecules. Vaseline and Aquaphor are commonly used brands of petrolatum. It can be used alone as an ointment or mixed in with other medications.

Photoaging: The naturally-occurring aging process that progresses during a lifetime of sun exposure.

Photochemotherapy: The addition of drugs to light therapy in order to intensify its effects.

Photosensitivity: Increased sensitivity to the sun's light or other UV sources.

Phototherapy: The use of light, whether from the sun or special light sources, to treat skin disease.

Phototoxicity: Condition of heightened sunburn response resulting from exposure to ultraviolet light.

Pigmentation: The colouring of the skin, hair, mucous membranes, and retina of the eye.

Pimecrolimus: A topical Im­munomodulator that can be used for psoriasis, especially on genitals and skin folds. It is sold under the trade name Elidel.

Placebo effect: The positive reaction to a pharmacologically inactive or neutral substance by a recipient who believes it will work.

Plaque: a scaly patch formed on the skin by psoriasis. Can be used interchangeably with "lesion."

Plaque psoriasis: The most common form of psoriasis - about 80% of people with psoriasis have this type. Plaque psoriasis can appear on any skin surface, although the knees, elbows, scalp, trunk and nails are the most common locations. It is characterized by well-defined patches of red raised skin. The flaky silvery white build up on top of the plaques is called scale; it is composed of dead skin cells. This scale comes loose and sheds constantly from the plaques. Skin affected with psoriasis is generally very dry, and other possible symptoms include skin pain, itching and cracking. The technical name for plaque psoriasis is psoriasis vulgaris (vulgaris means common).

Plasminogen activator: A substance that plays a role in the accumulation of white blood cells that is found at high concentrations in psoriatic skin.

Polyarthritis: A medical term refer­ring to arthritis in many (poly-) joints (-arthritis).

Post-inflammatory changes: Darker or lighter areas of skin that develop as a skin injury, such as psoriasis or an ordinary scrape, resolves.

Potency: A way to describe the strength of a medication. It may be measured by the concentration or amount used, or measured relative to a standard (i.e., hydrocortisone for topical steroids).

PPD test: A skin test for previous exposure to tuberculosis. Certain tu­berculosis proteins are injected un­der the skin, and after a few days the skin is checked to see if the body mounts a response (shown as a raised, red wheal). The PPD test can be positive in people who have had a tuberculosis vaccine as a child (given in some foreign countries), or expo­sure in the past. People with positive tests usually need a chest X -ray to check for any tuberculosis in the lungs.

Pre-authorization: Pre treatment clearance from a medical aid company to use a particular therapy. The process usually involves a physician corresponding with a medical aid company on a patient's behalf.

Predisposed: Susceptible, likely to get.

Prednisone: A type of cortisone (a so-called "stress hormone" naturally made by the body) that can be taken by mouth.

Prescription: A written direction from a physician for the preparation and administration of a remedy. This is required for the purchase of certain medications.

Prescription drug: A drug available only by the prescription of a physi­cian. These drugs have been formally tested and are regulated by the FDA.

Proliferation: Rapid growth and reproduction of parts, such as cells.

Pruritus: Itching.

Ps, Pso: Abbreviation used for psor­iasis.

PsA, PsoA: Abbreviation used for psoriatic arthritis.

Psoralen: Any of a number of drugs and other substances containing chemicals that react with ultraviolet (UV) light to cause darkening of the skin. A medicine that, when taken by mouth or put onto the skin, increases the skin's sensitivity to UVA light. In combination with UVA light, it is called PUVA and is used to treat psoriasis and other skin diseases.

Psoriasis: A reddish, scaly rash often located over the surfaces of the elbows, knees, scalp, and around or in the ears, navel, genitals or buttocks. Psoriasis is an autoimmune disease that is mediated by T lymphocytes. It is also a very common disease. Chronic plaque psoriasis affects approximately 2% of people around the world. About 10-15% of patients with psoriasis develop joint inflammation (inflammatory arthritis ). Treatment options include topical steroid creams, tar soap preparations, and exposure to ultraviolet light.

Psoriasis Area Severity Index (PASI): A measurement that com­bines BSA with a rating of the sever­ity of scaling, thickness, and redness in a particular area.

Psoriasis vulgaris: The medical name for the most common form of psoriasis ("vulgaris" means common). About 80% of people with psoriasis have this type. It is also called plaque psoriasis because of the characteristic plaques on the skin: well-defined patches of red raised skin that can appear on any area of skin, although the knees, elbows, scalp, trunk and nails are the most common locations. The flaky silvery white build up on top of the plaques is called scale; it is composed of dead skin cells. This scale comes loose and sheds constantly from the plaques. Skin affected with psoriasis is generally very dry, and other possible symptoms include skin pain, itching and cracking.

Psoriatic arthritis: A term for the several types of arthritis that can de­velop in people with psoriasis. It is distinct from other common types of arthritis and may need to be treated differently. Joint inflammation associated with psoriasis. Psoriatic arthritis is a potentially destructive and deforming form of arthritis that affects approximately 10% of persons with psoriasis.

Psychological: Relating to the mind. Like many diseases, psoriasis may have psychological effects on a person's self-esteem and emotions in addition to physical effects.

Psychosocial: Involving both the social and psychological aspects of a person's life. For example, psoriasis patients often report that the disease affects their self-confidence at work, at parties, or on dates.

Psychodynamics: The motivational and emotional forces, conscious and unconscious that shape a person's behaviours and attitudes.

Pulse treatment: The planned use of a very strong or very high-dose med­ication for a short period of time.

Punch biopsy: A biopsy that uses a small, specially designed punching tool shaped like a miniature "cookie cutter." This punch is usually deeper than a shave and lets the examining physician see further down into the skin.

Pus: Thick, opaque, usually yellowish-white fluid made up of dead tissue, dead bacteria, and white blood cells.

Pustular psoriasis: Psoriasis characterized by clearly defined, raised bumps on the skin that are filled with pus. This type of psoriasis is usually seen on the hands and feet, but may also affect larger areas of the body. It may occur in association with erythrodermic psoriasis.

Pustule: A small, circumscribed elevation of the skin containing pus.

PUVA: PUVA stands for psoralen (P) and ultraviolet A (UVA) therapy in which the patient is exposed first to psoralens (drugs containing chemicals that react with ultraviolet light) and then to UVA light.

Rash: Breaking out (eruption) of the skin. Medically, a rash is referred to as an exanthem.

Rebound: In reference to skin psoriasis: A severe and sudden change that occurs in psoriasis when systemic therapy is suddenly halted. This change leaves the patient's psoriasis in a significantly worse condition than before the treatment was started. Rebound may also include a change in the nature of the psoriasis, for example, from plaque to pustular form. In some cases, rebound may be recognized early as new onset, severe and extensive erythema

Recalcitrant: Stubbornly resistant to treatment. Example: Recalcitrant psoriasis.

Receptor: structures on the surface of cells that serve as docking sites for other cells or signalling molecules to relay information or trigger a reaction.

Remission: The period during which the symptoms of a disease decrease or subside.

Retinoids: Vitamin A derivatives often used in topical or oral psoriasis therapy.

Rheumatoid arthritis: A chronic autoimmune disease characterized by pain, stiffness, inflammation, swelling, and, sometimes, destruction of joints.

Rheumatologist: A physician who specializes in diseases of the immune system and the joints.

Rotational therapy: Rotating differ­ent therapies over time in order to maximize benefits while minimizing side effects that might accumulate.

Sacroiliac joint: The joints between the hip bones and the spine.

Salicylic acid: A substance obtained from plants (white willow back and wintergreen leaves) and also synthesized which is versatile and possesses bacteriostatic, fungicidal, and keratolytic actions. It is often used in psoriasis preparations due to its keratolytic properties.

SAPFORUM: The South African Psoriasis Association, the national body in South Africa that acts in the interests of all psoriasis sufferers in South Africa.

Scale: A silvery-white build up of dead skin cells that covers plaques in the most common form of psoriasis. These scales come loose from the plaque and are shed.

Scaling: Abnormal shedding or accumulation of an upper layer of skin (the stratum corneum).

Scalp psoriasis: Plaque psoriasis that appears on the scalp. It is often itchy and most visible around the ears and hairline. The constant flaking and shedding of dead skin cells give the appearance of severe dandruff.

SCAT: Short-contact anthralin therapy.

Seborrheic Dermatitis: Dermatitis of the scalp, face, ears and sometimes the chest. Mild cases are known as dandruff.

Self-deprecation: Belittling or undervaluing oneself.

Self-help: Helping oneself to improve his or her quality of life.

Sequential therapy: Transitioning from one therapy to another to maxi­mize certain treatment characteris­tics. An example would be starting with a medication that works rapidly to initiate clearing and following it with a slower-acting medication that may be safer for long-term use.

Severe psoriasis: Psoriasis that covers more than 10% of the skin's surface. The severity of psoriasis is also measured by the impact of the disease on a person's quality of life.

Shark cartilage: A food supplement thought by some to be useful in treating psoriasis.

Shave biopsy: A biopsy performed with a razor by cutting off a superfi­cial piece of the skin.

Side effect: An undesired effect of a medication, problems that occur when treatment goes beyond the desired effect or problems that occur in addition to the desired therapeutic effect.

Skin: The skin is the body's outer covering. It protects us against heat and light, injury, and infection. It regulates body temperature and stores water, fat, and vitamin D. Weighing about 6 pounds, the skin is the body's largest organ. It is made up of two main layers; the outer epidermis and the inner dermis.

Skin biopsy: The surgical removal of a piece of skin (often the size of a pencil eraser) for examination under a microscope. A biopsy is often done to diagnose a skin disease.

Skin thinning: A condition in which the skin atrophies due to any variety of causes, including overuse of topical steroids.

Solution: A mixture of a medicine in water, or water with alcohol, for topi­cal use, often on hair bearing areas. It is sometimes referred to as a "lotion".

Spondylarthropathy: Inflammation of the spine and hip joints.

Squamous cell carcinoma (SCC): The second most common skin can­cer, it arises from the epidermis and resembles the squamous cells that comprise most of the upper layers of skin. This may occur anywhere on the body, including the mucous mem­branes, but are most common in areas exposed to the sun.

Steroids: A large class of pharmaceu­tical agents that chemically resemble cholesterol. Two well-known types are glucocorticoid steroids that are used to reduce inflammation, and an­abolic steroids, which are often used (illegally) in athletics. A general class of chemical substances that are structurally related to one another and share the same chemical skeleton (a tetracyclic cyclopenta[a]phenanthrene skeleton).

Stratum corneum: Outermost layer of the epidermis composed mainly of keratin.

Streptococcus: A group of bacteria, familiarly known as strep, that cause a multitude of diseases. The name comes from the Greek strepto- meaning twisted + kokkos meaning berry, and that is exactly what strep look like under the microscope, like a twisted bunch of little round berries. Illness caused by strep includes strep throat, strep pneumonia, scarlet fever, rheumatic fever (and rheumatic heart valve damage), glomerulonephritis, the skin disorder erysipelas, and PANDAS.

Streptococcal sore throat (also known as "strep throat"): A type of bacterial infection of the throat that, in susceptible individuals, may trigger the onset of psoriasis, usually in a form called guttate psoriasis.

Stress: Forces from the outside world impinging on the individual. Stress is a normal part of life that can help us learn and grow. Conversely, stress can cause us significant problems.

Stressors: Any of a number of factors that can cause an individual to experience physical or emotional stress.

Striae: Linear, scar-like portions of skin, commonly called "stretch marks." These may occur from prolonged use of topical steroids.

Subcutaneous: The tissue just below the surface of the skin. Some medi­cines are injected into this area.

Sunburn: Sunburn is an inflammation of the skin that develops in response to exposure to ultraviolet (UV) radiation from the sun or from tanning beds and booths that emit UV radiation. Sunburn is manifested by reddened, painful skin that may develop blisters.

Superinfection: An infection that develops following another skin prob­lem, such as psoriasis or eczema, for example. This infection is often more persistent or more difficult to treat than an infection on previously healthy skin.

Superpotent: The highest strength classification of corticosteroids (Class 1).

Support group: A gathering of people who share a common concern and who meet regularly to offer one another emotional support and understanding.

Suture: A medical term for a stitch. Some sutures may need to be re­moved, while others can dissolve on their own.

Synergism: When the benefits of two medications used together are even greater than what they would be if they were simply added because they complement each other in some way.

Systemic: Affecting the entire body internally. A systemic disease such as diabetes can affect the whole body.

Systemic absorption: The absorption of a medication through the skin, for example, into the blood where it reaches the entire body.

Systemic effects: Effects of a med­ication that reach throughout the body and therefore may affect organs or systems beyond the skin or joints.

Systemic medication: A medication given, either by mouth or by injec­tion, to reach the entire body.

Systemic steroids: Steroids that are given orally, by injection, or by vein and therefore have many different ef­fects on the body.

Systemic treatment: Systemic chemotherapy employs drugs that travel through the bloodstream and reach and affect cells all over the body.

T cell: A type of white blood cell that is of key importance to the immune system and is at the core of adaptive immunity, the system that tailors the body's immune response to specific pathogens. The T cells are like soldiers who search out and destroy the targeted invaders.

T-cell receptors: Molecules on the surface of T cells that are the sites for macrophages to "present" antigens to the T cell and trigger an immune response.

Tachyphylaxis: The phenomenon where a medication becomes less ef­fective over a long period of use.

Tacrolimus: A topical immunomod­ulator, usually used for eczema that can be effective in genital and other types of psoriasis. Also comes in an oral form used in transplantation and sometimes in psoriasis. It is similar to cyclosporine in action.

Tar: A brown or black material, liq­uid or semi-solid in consistency, de­rived from coal, petroleum, wood, or other organic material. Used on the skin, it has immunosuppressant qualities and has long been used to treat psoriasis.

Tazarotene: A topical Vitamin A de­rivative developed to treat psoriasis. An oral form is in development. It is sold under the trade name Tazorac.

Therapeutic: Having the power to improve or heal.

Therapy holiday: A scheduled time without therapy, planned by a patient and his or her physician.

Topical: Pertaining to a particular surface area.

Topical agent/treatment: A topical agent is applied to a certain area of the skin and is intended to affect only the area to which it is applied. Whether its effects are indeed limited to that area depends upon whether the agent stays where it is put or is absorbed into the blood stream.

Toxicity: The potential of a drug or treatment to cause harmful side effects.

Tumour Necrosis Factor (TNF): A protein in the body involved in inflammatory processes. When overproduced in the body, it also damages tissue in and around the joints of people with psoriatic arthritis.

Type II collagen: The kind of collagen found in joints in the human body.

Trigger: Something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus.

Ultraviolet (UV) radiation: Invisible rays that are part of the energy that comes from the sun. It is made up of two types of rays: UVA and UVB.

UVA: A particular wavelength of light that is used in combination with a medication called psoralen to treat psoriasis. One of the three types of invisible light rays (together with ultraviolet B and ultraviolet C) given off by the sun.

UVB: A particular wavelength of light that can be used alone to treat psoriasis. One of the three types of invisible light rays (together with ultraviolet A and ultraviolet C) given off by the sun.

Vehicle: The base or inactive product into which a medication is mixed. Ex­amples include petrolatum, cream, and foam.

Visualization: A technique thought to aid in self-relaxation and stress reduction that depends upon the ability to imagine oneself in a calmer, less stressful situation. In some cases, this can include picturing oneself in a symptom-free state.

Vitamin A: Vitamin A is retinol. Carotene compounds (found, for example, in egg yolk, butter and cream) are gradually converted by the body to vitamin A (retinol). A form of vitamin A called retinal is responsible for transmitting light sensation in the retina of the eye.

Vitamin D: A steroid vitamin which promotes the intestinal absorption and metabolism of calcium and phosphorus. Under normal conditions of sunlight exposure, no dietary supplementation is necessary because sunlight promotes adequate vitamin D synthesis in the skin. Deficiency can lead to bone deformity (rickets) in children and bone weakness (osteomalacia) in adults.

Vitamin D3: A vitamin produced by the body when exposed to ultraviolet light or obtained from dietary sources. Vitamin D3 is a hormone that has an important role in calcium and phosphorus metabolism. Technically, vitamin D3 is not a vitamin because the body can produce it. It is also known as cholecalciferol.

Wavelength: The length of a particu­lar wave of light. These lengths vary in different types of light (ultraviolet vs. visible light or different types of UV light, for example) and help de­termine how far into the skin these waves will penetrate.

White blood cell: One of the cells the body makes to help fight infections. There are several types of white blood cells (leukocytes). The two most common types are the lymphocytes and neutrophils (also called polymorphonuclear leukocytes, PMNs, or "polys").

Woronoff Ring: A ring of pale-­appearing skin that may be visible at the edge of a psoriasis plaque.

Yoga: A program of stretching and relaxation that can help reduce stress.

Zinc: A natural element often found in multiple vitamin tablets or sold on its own for a variety of conditions, including psoriasis.