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 buildup 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:

• An unhealthy state, such as in “this is a progressive condition.”
• A state of fitness, such as “getting into condition.”
• Something that is essential to the occurrence of something else; essentially a “precondition.”
• 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.

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: 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. It is characterized by periodic, widespread, fiery redness of the skin, accompanied by severe itching, pain, and swelling.

Etanercept: A biologic therapy that works by inhibiting TNF-a, commonly 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 a 311 nm wavelength, similar to the wavelength of UVB. It is effective for treating psoriasis in local areas, administered in a dermatologist’s office.

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

Exfoliative psoriasis: Another name for erythrodermic psoriasis, involving widespread skin exfoliation with redness, severe itching, and swelling.

Exotoxin: A poison released from a living microorganism.

Fish oils: Oils rich in omega-3, derived from fish, often taken as a dietary supplement for their anti-inflammatory properties.

Flare-up: A worsening of a disease’s symptoms.

Flexural psoriasis (inverse psoriasis): Psoriasis that occurs in skin folds, such as the underarms or groin, causing discomfort.

Foam: An alcohol- or water-based vehicle in which an active ingredient, like a topical steroid, can be mixed for application on the skin.

Focus meditation: A stress-reduction technique involving extended contemplation or thought.

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

Food and Drug Administration (FDA): The USA federal agency that regulates the safety of food, drugs, and other products.

Food supplements: Substances added to the diet that are believed to have health benefits.

Fusion protein: A protein containing amino acid sequences from two sources, such as human and mouse, often used for therapeutic purposes.

Gastroenterologist: A physician specializing in diseases of the digestive system.

Gene: The segment of DNA on a chromosome that contains the information necessary to make a protein.

Genes and base pairs: Genes are short sections of DNA arranged in sequences that encode the “recipe” for proteins, determined by paired chemicals along DNA strands.

Gene therapy: The injection of healthy genes into the bloodstream to correct hereditary diseases.

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

Goeckerman Regimen: A treatment combining topical tar and light therapy, often provided in specialized psoriasis treatment centers.

Gold: A precious metal used as an oral or injectable treatment for psoriatic arthritis, requiring careful monitoring.

Guided imagery: A relaxation technique involving mental visualizations to reduce stress.

Guttate psoriasis: A type of psoriasis characterized by drop-like lesions, often triggered by infections.

Hand/foot therapy: A specialized light treatment for psoriasis on the hands and feet.

Heliotherapy: Sunlight exposure therapy for psoriasis.

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

Heredity: The transmission of traits from parents to offspring.

Holistic medicine: An approach that addresses physical, spiritual, and emotional needs.

Human leukocyte antigen (HLA) system: Proteins on white blood cells involved in immune response.

Homeopathy: A medical practice using tiny doses of substances to stimulate the body’s natural defenses.

Hyperkeratinization: Thickening of the skin’s outer layer caused by overactive keratinocytes, common in psoriasis.

Home phototherapy: Ultraviolet light treatment administered at home under medical supervision.

Hormone: A chemical substance regulating organ or tissue activity.

Hydration: The process of increasing moisture or water content.

Hydroxyurea: An anti-cancer drug also used to treat psoriasis, often combined with acitretin for enhanced effectiveness.

Hyperplasia: An abnormal increase in cell numbers in tissue.

Idiosyncrasy: A unique or unusual individual reaction to a drug.

IFPA: The International Federation of Psoriasis Associations, an umbrella organization for national psoriasis associations worldwide.

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

Immune: Protected against infection.

Immune deficiency: The inability to maintain a functional immune system.

Immune response: The body’s reaction to foreign substances.

Immune system: A collection of cells and proteins protecting the body from harmful microorganisms, playing roles in autoimmune diseases and organ rejection.

Immunologic: Pertaining to the immune system.

Immunomodulator: A medication that alters the immune system’s response.

Immunosuppressive: A drug that dampens immune activity.

Infection: The presence of a parasitic organism within the body.

Inflammation: The body’s response to injury or infection, characterized by redness, warmth, swelling, and pain.

Inheritance: The transmission of genetic material from parents to offspring.

Informed consent: A document outlining a participant’s involvement in a clinical trial, including risks and expectations.

Institutional Review Board (IRB): A group that ensures the ethical treatment of clinical trial participants.

Interferons: Proteins produced in response to viral exposure, with therapeutic applications in diseases like psoriasis.

Intergluteal: Between the buttocks.

Interleukin: Cytokines that promote immune cell growth.

Intertriginous psoriasis: Psoriasis affecting areas like the armpits and groin.

Intramuscular: Administered into a muscle.

Intravenous: Administered into a vein.

Inverse psoriasis: Psoriasis in skin folds, often irritated by friction.

Iritis: Inflammation of the eye, sometimes linked to autoimmune diseases. Also called anterior uveitis.

Itching: An uncomfortable sensation in the skin that creates a desire to scratch.

Joint: The area where two bones connect for movement.

Keratin: A protein that forms the main structure of skin, hair, and nails.

Keratinocyte: A type of skin cell; its excessive growth leads to psoriasis lesions.

Keratolysis: A condition in which the outer layer of the skin sheds regularly.

Keratolytic: A substance that helps remove dead skin cells from the epidermis and breaks down keratin in scales, such as alpha hydroxy acids.

Koebner Phenomenon: The appearance of new psoriasis lesions at sites of skin trauma. Also called Koebnerization.

Laser: A device that emits focused light energy, often used in medical treatments.

Latent tuberculosis: Tuberculosis bacteria present in the body without causing active disease. Can reactivate during immunosuppressive therapy.

LCD: Liquor carbonis detergens, a tar preparation used for psoriasis treatment.

Lesion: A patch of skin affected by psoriasis.

Linkage: The association of genes located close together on a chromosome.

Lipids: Fats in the bloodstream, such as cholesterol and triglycerides.

Liquor carbonis detergens (LCD): Refined coal tar extract used to treat psoriasis.

Lithium: A drug used to treat bipolar disorder, known to aggravate psoriasis in some individuals.

Liver: A vital organ involved in digestion, detoxification, and protein synthesis.

Liver biopsy: The removal of liver tissue for examination to diagnose diseases.

Liver dysfunction: Impaired liver function.

Local effects: Effects of medication restricted to the site of application.

Lotion: A water-based topical preparation used to treat skin conditions.

Lymphocytes: White blood cells essential for immune system function.

Macerate: To soften by soaking.

Macrophage: An immune cell that engulfs foreign particles and triggers T cell activation.

Maintenance program: Ongoing treatment to keep a disease in remission.

Malignant melanoma: A severe form of skin cancer; early detection is crucial for treatment.

Mapping: Determining the relative position of genes on a chromosome.

Marker: A known gene used as a reference point in genetic studies.

Medical dermatology: The branch of dermatology focused on medical skin conditions.

Melanocyte: A skin cell that produces melanin, the pigment that gives skin its color.

Methotrexate: A cytotoxic drug used to treat cancer and autoimmune diseases, including psoriasis.

Mild psoriasis: Psoriasis affecting a small area of the body.

Milk thistle: A herbal remedy believed to support liver function.

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

Modified Goeckerman regimen: A version of the Goeckerman regimen using less tar or ointment.

Monoclonal antibody (MAb): Laboratory-engineered antibodies that target specific molecules for therapeutic purposes.

Mucous membranes: The moist linings of body cavities like the mouth and nose.

Multifactorial: Resulting from multiple interacting factors.

Nail psoriasis: Psoriasis affecting the nails, causing pitting and discoloration.

Narrow-band UVB: A specific range of UV light (311-313 nm) effective for psoriasis treatment.

National Psoriasis Foundation: A U.S.-based organization supporting people with psoriasis.

Naturopathy: A natural therapy approach based on the belief that disease is caused by excess toxins.

Neutrophil: A type of white blood cell that fights bacterial infections.

Non-steroidal anti-inflammatories (NSAIDs): Painkillers like ibuprofen that reduce inflammation without steroids.

Nutritional supplement: A product added to the diet, such as vitamins or minerals, to promote health.

Occlusion: Covering the skin to enhance the absorption of topical treatments.

Off-label prescribing: Using a medication for purposes other than those approved by regulatory bodies.

Oil spot: Yellow-brown discoloration on nails caused by psoriasis.

Ointment: A topical preparation with an oil base used to treat skin conditions.

Oligoarthritis: Arthritis affecting a few joints.

Onycholysis: Nail separation from the nail bed, often seen in psoriasis.

Oral: Relating to the mouth.

Oral medication: Medicine taken by mouth.

Oral tolerization: Ingesting a foreign protein to build tolerance to it.

Over-the-counter (OTC): Medications available without a prescription.

Pain: An unpleasant sensation caused by nerve stimulation.

Paint PUVA: A type of PUVA therapy in which psoralen is applied directly to the skin.

Palmar-plantar psoriasis: Psoriasis affecting the hands and feet.

Parenterally: Administering medication by injection or infusion.

PASI Score: A measurement of psoriasis severity based on the area affected and the severity of symptoms.

Pathologist: A doctor who examines tissues and cells to diagnose diseases.

Pathology report: A formal medical report following the examination of a tissue sample.

Petrolatum: An inert, semi-solid substance used as a base for ointments.

Photoaging: Skin aging caused by prolonged sun exposure.

Photochemotherapy: Combining drugs with light therapy to enhance effectiveness.

Photosensitivity: Increased sensitivity to light, often as a side effect of medication.

Phototherapy: Light-based treatment for skin diseases like psoriasis.

Phototoxicity: Increased skin sensitivity to sunlight, causing sunburn-like symptoms.

Pigmentation: The natural color of the skin, hair, and eyes.

Pimecrolimus: An immunomodulator used topically for psoriasis treatment, sold under the trade name Elidel.

Placebo effect: A positive response to an inactive substance believed to be effective.

Plaque: A scaly patch on the skin caused by psoriasis.

Plaque psoriasis: The most common form of psoriasis, characterized by raised, red patches covered with silvery scales.

Plasminogen activator: A substance that accumulates in psoriatic skin, aiding in inflammation.

Polyarthritis: Arthritis affecting multiple joints.

Post-inflammatory changes: Skin discoloration that occurs after inflammation subsides.

Potency: A measure of a medication’s strength.

PPD test: A skin test used to detect previous exposure to tuberculosis by injecting proteins under the skin and checking for a reaction.

Pre-authorization: Pre-treatment approval from a medical aid or insurance company to cover a specific therapy.

Predisposed: Likely or susceptible to develop a certain condition or disease.

Prednisone: A corticosteroid taken orally to reduce inflammation.

Prescription: A written order from a healthcare provider for medication or treatment.

Prescription drug: Medication available only through a healthcare provider’s prescription.

Proliferation: Rapid growth or reproduction of cells.

Pruritus: The medical term for itching.

Ps, Pso: Abbreviations for psoriasis.

PsA, PsoA: Abbreviations for psoriatic arthritis.

Psoralen: A drug that increases sensitivity to UVA light, used in PUVA therapy for skin diseases.

Psoriasis: An autoimmune disease that causes red, scaly patches on the skin, commonly affecting the elbows, knees, scalp, and other areas.

Psoriasis Area Severity Index (PASI): A score used to measure the severity of psoriasis based on body coverage and symptoms.

Psoriasis vulgaris: Another term for plaque psoriasis, the most common type of psoriasis.

Psoriatic arthritis: A form of arthritis that occurs in some people with psoriasis, causing joint inflammation and pain.

Psychological: Pertaining to the mind and mental health, including emotional impacts of diseases like psoriasis.

Psychosocial: Involving both psychological and social factors, such as how a disease affects self-esteem and social interactions.

Psychodynamics: The interplay of conscious and unconscious emotional forces influencing behavior and attitudes.

Pulse treatment: Short-term use of high-dose medication to control symptoms quickly.

Punch biopsy: A biopsy using a small cylindrical tool to remove deeper layers of the skin for examination.

Pus: A yellowish fluid composed of dead tissue, bacteria, and white blood cells.

Pustular psoriasis: A severe form of psoriasis characterized by pus-filled bumps on the skin.

Pustule: A small, elevated, pus-filled lesion on the skin.

PUVA: A therapy combining psoralen with UVA light exposure to treat psoriasis.

Rash: An outbreak of irritated or inflamed skin.

Rebound: A worsening of psoriasis symptoms after discontinuing systemic treatment.

Recalcitrant: Resistant to treatment.

Receptor: A structure on a cell surface that binds with specific molecules to trigger a response.

Remission: A period during which disease symptoms subside or disappear.

Retinoids: Vitamin A derivatives used to treat skin conditions like psoriasis.

Rheumatoid arthritis: A chronic autoimmune disorder causing joint inflammation and pain.

Rheumatologist: A doctor specializing in the treatment of autoimmune diseases and joint disorders.

Rotational therapy: Switching between different therapies over time to improve effectiveness and reduce side effects.

Sacroiliac joint: The joint connecting the spine to the pelvis.

Salicylic acid: A compound with keratolytic properties, used to remove scales in psoriasis treatment.

SAPSA: The South African Psoriasis Association, representing psoriasis sufferers in South Africa.

Scale: A buildup of dead skin cells, often seen on plaques in psoriasis.

Scaling: Excessive shedding of the outer layer of skin.

Scalp psoriasis: Psoriasis that affects the scalp, often causing itching and dandruff-like flaking.

SCAT: Short-contact anthralin therapy for psoriasis.

Seborrheic Dermatitis: A condition causing scaly patches and dandruff on the scalp and face.

Self-deprecation: Belittling oneself.

Self-help: Activities aimed at improving personal well-being.

Sequential therapy: Using one treatment initially and transitioning to another to maintain improvement.

Severe psoriasis: Psoriasis covering more than 10% of the skin’s surface.

Shark cartilage: A supplement thought to help with psoriasis.

Shave biopsy: A superficial biopsy using a razor to remove a thin piece of skin.

Side effect: An unintended effect of medication or treatment.

Skin: The body’s largest organ, providing protection and regulating temperature.

Skin biopsy: A procedure to remove a sample of skin for diagnostic examination.

Skin thinning: A condition where the skin becomes fragile, often due to overuse of topical steroids.

Solution: A liquid preparation of medication for topical use.

Spondylarthropathy: Inflammation affecting the spine and large joints.

Squamous cell carcinoma (SCC): A common type of skin cancer arising from the epidermis.

Steroids: A class of drugs used to reduce inflammation.

Stratum corneum: The outermost layer of the epidermis.

Streptococcus: A type of bacteria that can cause infections, including strep throat.

Streptococcal sore throat: A bacterial throat infection that can trigger guttate psoriasis in some people.

Stress: A physical or emotional response to challenging situations.

Stressors: Factors that trigger physical or emotional stress.

Striae: Linear marks on the skin, commonly known as stretch marks.

Subcutaneous: Under the skin.

Sunburn: Skin inflammation caused by overexposure to ultraviolet radiation.

Superinfection: A secondary infection occurring after or on top of another condition.

Superpotent: The highest strength classification of corticosteroids.

Support group: A group of people who share similar experiences and offer emotional support to each other.

Suture: A stitch used to close a wound.

Synergism: When two medications used together have a stronger effect than when used individually.

Systemic: Affecting the entire body.

Systemic absorption: The process by which a medication enters the bloodstream.

Systemic effects: Effects that spread throughout the body beyond the targeted area.

Systemic medication: Medication taken orally or injected to affect the whole body.

Systemic steroids: Steroids administered orally or by injection to treat inflammation throughout the body.

Systemic treatment: A treatment that affects the whole body, such as chemotherapy.

T cell: A white blood cell essential to the immune system’s function.

T-cell receptors: Molecules on T cells that recognize antigens and trigger an immune response.

Tachyphylaxis: A decrease in medication effectiveness over time.

Tacrolimus: An immunomodulator used topically for eczema and psoriasis.

Tar: A black or brown substance used in psoriasis treatment.

Tazarotene: A topical retinoid used to treat psoriasis.

Therapeutic: Having a healing effect.

Therapy holiday: A planned break from treatment.

Topical: Applied to the surface of the skin.

Topical agent/treatment: A treatment applied to the skin, intended to affect only the applied area.

Toxicity: The degree to which a substance can cause harm.

Tumor Necrosis Factor (TNF): A protein involved in inflammation, targeted by some psoriasis treatments.

Type II collagen: The type of collagen found in joints.

Trigger: Something that initiates or worsens a disease or symptom.

Ultraviolet (UV) radiation: Invisible rays from the sun that can be used therapeutically.

UVA: A type of UV light used in PUVA therapy.

UVB: A type of UV light used alone to treat psoriasis.

Vehicle: The base in which a medication is mixed for topical use.

Visualization: A technique for stress reduction by imagining peaceful scenarios.

Vitamin A: A vitamin important for skin health, sometimes used in psoriasis treatments.

Vitamin D: A vitamin involved in calcium metabolism, used in some psoriasis therapies.

Vitamin D3: A form of vitamin D produced by the body or obtained through diet.

Wavelength: The length of a wave of light, which determines its effect on the skin.

White blood cell: A component of the immune system that fights infections.

Woronoff Ring: A pale ring around psoriasis plaques.

Yoga: A practice involving physical postures, breathing, and meditation to reduce stress.

Zinc: A mineral often included in supplements for psoriasis treatment.