dermatitis

n.

an inflammatory condition of the skin caused by outside agents (compare eczema, an endogenous disease in which such agents do not play a primary role). Primary irritant dermatitis may occur in anyone who has sufficient contact with such irritants as acids, alkalis, solvents, and (especially) detergents. It is the commonest cause of occupational dermatitis in hairdressers, nurses, cooks, etc. (See also napkin rash.) In allergic contact dermatitis skin changes resembling those of eczema develop as a delayed reaction to contact with a particular allergen, which may be present at low concentrations. The commonest example in women is nickel dermatitis from jewellery, jeans studs, etc.; in men chromium dermatitis is relatively common (cement is the usual source). Treatment of dermatitis depends on removing the cause, which is not always possible.

Dermatitis herpetiformis is an uncommon very itchy rash with symmetrical blistering, especially on the knees, elbows, buttocks, and shoulders. It is associated with gluten sensitivity and responds well to treatment with dapsone.