What do all these medical terms mean?

A brief but hopefully useful glossary of some of the terms and frequently used initials which may help you when reading medical information.
With acknowledgements to Psoriasis at Your Fingertips for some of the definitions.

Adherence Whether a patient sticks to their treatment programme
Compliance Much the same as adherence – whether a patient does as they are told.
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.
Flexures The areas where the limbs bend, bringing together two surfaces e.g. the creases at the front of the elbows, the back of the knees and the groin.
Guttate A term used to describe lesions on the skin that are shaped like drops of water.
Immune system The body’s defence system against outside attackers. The immune system fights off infection and produces antibodies that will protect against future attack.
Interleukin-2 One of a group of special proteins that control the immune response. Interleukin–2 stimulates the T_Lymphacites that are active in the skin.
Keratinocytes Types of cells that make up over 95% of the epidermis
Koebner’s Phenomen This describes a reaction in the skin that occurs in psoriasis and some other skin diseases where typical lesions of the diseases appear in areas of the skin damaged by injury such as scratches, cuts or burns
Phototherapy Treatment with light – usually ultra violet light
Plaque A raised patch on the skin more than 2cms. across
Steroids A particular group of chemicals, which includes very important hormones, produced naturally by the body and also many drugs used for a wide range of medical purposes. In psoriasis the sub group of steroids with which we are concerned is the corticosteroids. 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 therapy Drugs given by mouth or injection that affect the whole body
Topical Treatments that are applied to the skin rather than being taken internally
Triggers Factors that may bring on psoriasis but do not cause psoriasis

And some of those initials you may come across
BAD British Association of Dermatologists
BBUVB Broadband UtraViolet B
NBUVB Narrowband UtraViolet B
OPD Out Patient Department
OTC Over the Counter ( treatments available with no prescription)
PASI Psoriasis Area and Severity Index
PCG Primary Care Group
PCT Primary Care Trust
PDI Psoriasis Disability Index
POM Prescription Only Medication
PUVA Psoralen and UVA Treatment
RCT Randomised Control Trial
RePUVA Retinoid plus Psoralen and UVA Treatment
SCC Skin Care Campaign

Biologics
Adalimumab - Humira
Efalizumab - Raptiva
Etanercept - Enbrel
Infliximab - Remicade