Tests and terminology in psoriasis

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Adherence- when a patient follows their advised treatment programme
Anthralin a topical treatment prescribed for the management of mild to moderate psoriasis
Antibody- a protein produced by immune system cells that binds to antigens on foreign particles/bodies allowing other elements of the immune system to attack, destroy or remove them
Antigens - the ‘fingerprint’ detected by the immune system that is found on every potentially harmful organism that enters the body.


Biological therapy- drugs made from natural proteins using biotechnology
Biotechnology - use of recombinant DNA, cell fusion, and new bioprocessing techniques applied to research and product development.


Cell - an organism that contains all the genetic information required to make a life form
Clinical trial - investigational studies of new treatments, new uses of existing treatment, or new screening methods to detect disease
Coal tar bath - coal tar solution is added to bath water for great coverage and penetration, used to treat the scaling, inflammation and itching of psoriasis and other skin disorders
Compliance - much the same as adherence - whether a patient carries out what they are advised
Cyclosporin - a prescription drug that decreases the body's immune response, used in the treatment of psoriasis
Cytokine - messengers that carry biochemical signals to regulate local and systemic immune responses, inflammatory reactions, wound healing, formation of blood cells, and any other biological processes. In psoriasis, cytokines carry messages that promote overly rapid development of skin cells.


Dermis - the deep layer of skin.


Emollient - an agent that soothes and softens the skin; also known as a moisturiser
Epidermis - the outer layer of skin
Erythroderma - an abnormal reddening, flaking and thickening of the skin, affecting a wide area of the body
Erythrodermic - intense scaling and inflammation of the skin
Erythrodermic psoriasis - psoriasis characterised by severe redness, scaling and shedding of the skin
Exfoliation - removing dead cells from the skin’s surface


Flexures - the areas where the limbs bend, bringing together two surfaces, for example, the front of the elbows and the back of the knees.


Gene - the material that forms the biologic code for all life forms
Guttate - a term used to describe small, dot-like lesions on the skin that are shaped like drops of water
Guttate psoriasis- psoriasis characterised by red, drop-like dots on the skin


Helper T-cells - cells that travel through the blood looking for antigens, when one is encountered they trigger other immune cells to attack
Human leucocyte antigen (HLA) - immune system markers strongly associated with the causes of psoriasis.


Immune system - the biochemical complex that protects the body against infections and other foreign bodies that lead to illness
Immunomodulatory drugs - drugs that alter the function of the immune system
Infection - the invasion of the body by microorganisms that reproduce and multiply, causing disease
Inflammation - reaction by tissue, for example skin, in response to infection or injury, usually involving reddening and swelling
Informed consent - the process by which a volunteer for a clinical trial agrees to participate after being fully informed regarding purposes of the trial, risks and benefits associated with participation in the trial, and whether volunteers will be randomised to receive treatment or placebo
Inverse psoriasis - psoriasis characterised by smooth, inflamed lesions in body folds.


Joint inflammation - can be present with psoriasis as psoriatic arthritis.


Keratinocyte - a type of skin cell making up over 95% of the epidermis, accelerated growth of these cells leads to the development of psoriasis lesions
Keratolytic - an agent that promotes the shedding of the epidermis at regular intervals
Killer T-cells - cells in the immune system that actively target and destroy cells perceived as foreign
Koebner’s phenomenon - psoriatic lesions that appear at the site of injury, infection or other skin problem.


Leukocytes - a type of white blood cell (involved in the immune system)
Lesions - a wound or injury to the skin, for example, a patch of skin affected by psoriasis


Macrophage - cells that destroy foreign antigens and initiate T-cell formation, also called an ‘antigen-presenting cell’
Methotrexate - an agent prescribed for the treatment of moderate to severe psoriasis
Monoclonal antibody (MAb) - antibodies created with biotechnology techniques in laboratories that are highly specific and ‘recognise’ and target only one molecule, such as a receptor, or antigen.


Non-contagious - incapable of being transmitted from person to person.


Onycholysis – this is where the nail becomes detached from the underlying nail bed and a gap develops under the nail.When it starts there is a white or yellowish patch at the tip of the nail, and this then extends down to the cuticle.
OTC Over the Counter (treatments available with no prescription)


PASI - Psoriasis Area and Severity Index
Parakeratosis- the process by which psoriatic skin cells continuously form and move upward to the skin surface faster than they can be incorporated into the skin, resulting in them scaling off
Pastes - ointments in which powder is suspended
PCG - Primary Care Group
PCT - Primary Care Trust
PDI - Psoriasis Disability Index
Photo-chemotherapy - when light therapy and drug therapy are used in combination
Phototherapy - treatment with artificial ultraviolet light
Placebo - an inactive drug with no medicinal value, used as method of ‘control’ in clinical trials
Plaque - a flattish, raised, scaly patch on the skin more than 2 cm across and formed by psoriasis
Plaque psoriasis - psoriasis characterised by red, silvery-white, scaly skin lesions, accounting for about 80 percent of all cases
POM - Prescription Only Medication
Psoriasis - a persistent skin disease in which the skin becomes inflamed, producing red, thickened areas with silvery scales, most often on the scalp, elbows, knees, and lower back
Psoriatic arthritis - a genetically driven autoimmune disease affecting large and small joints that occurs in less than 10 percent of psoriasis patients
Pustular psoriasis - psoriasis characterised by pus-like blisters on the skin usually occurring on the hands or feet
Pustular - pus-filled lesions and intense scaling.
PUVA - Psoralen and UV-A Treatment


QALY - a quality-adjusted life-year, a calculation which takes into account both quantity and the quality of life generated by healthcare interventions.


Receptor - structures on the surface of cells that serve as docking sites for other cells to relay information or trigger a reaction
Remission - the period during which the symptoms of a disease decrease or subside
Retinoids - vitamin A derivatives used in the prevention and treatment of various skin problems.


Scales - thin flakes on the skin surface
Shake lotions - a combination of a powder and liquid that must be shaken before being applied to the skin
Steroid - an abbreviated word for corticosteroids, which are powerful drugs used to control inflammation and itching of the skin. Very often this is shortened to ‘steroids’ causing people to confuse their skin treatments with the anabolic steroids used for body-building
Subcutaneous - beneath the skin
Systemic - referring to the body as a whole
Systemic therapy - drugs that affect the whole body.


T-cells - cells that either initiate the immune response (helper T-cells) or actively target and destroy cells perceived as foreign (killer T-cells)
T-cell receptors - molecules on the surface of T-cells that are the sites for macrophages to ‘pre- sent’ antigens to the T-cell and trigger an immune response
T-lymphocytes - a type of white blood cell within the immune system
Topical - treatments that are applied to the skin rather than being taken internally
Trigger - an environmental factor that acts together with genetic predisposition to cause the onset or worsening of psoriasis
Tumour necrosis factor (TNF) - a protein in the body involved in inflammatory processes that also damages tissue in and around the joints of people with psoriatic arthritis.


Ultraviolet light (UV) - the part of light that can be used to treat psoriasis but can also cause sunburn.
UV-A - Ultraviolet light with wavelengths ranging from 320 to 400 nm
UV-B - Ultraviolet light with wavelengths ranging from 290 to 320 nm


Vitamin D analogues, calcipotriol, calcitriol and tacalcitol, should not be confused with vitamin tablets or liquids that you may take as dietary supplements. Whilst their chemical structure may be based on a vitamin D3 molecule they have been modified to have a completely different effect.

Vulgaris - is latin for common and used for the most widespread plaque version, called psoriasis vulgaris.


Wax and wane - to come and go, often how psoriasis patients decribe an acute flare or relapse.

White blood cell - are the cells of the immune system that defend the body against infectious diseases.



Yellowish patch or onycholysis – this is where the nail becomes detached from the underlying nail bed and a gap develops under the nail.When it starts there is a white or yellowish patch at the tip of the nail, and this then extends down to the cuticle.


Zorac - topical vitamin D treatment

Originally published as part of the Psoriatic Care Fact File
Published By PAPAA Publications ©2004