Introduction to dermatitis

Dermatitis is a nonspecific inflammatory response of the skin, presenting as an erythematous rash that is usually itchy and sometimes scaly. Dermatitis affects about 1 in 5 people during their lifetime. Most patients have isolated short episodes that respond well to treatment. Some types of dermatitis are chronic (eg atopic dermatitis, contact dermatitis).

The cause of dermatitis can be endogenous (eg atopic, seborrhoeic, discoid, asteatotic, venous and hand or foot dermatitis, lichen simplex) or exogenous (eg contact dermatitis [irritant, allergic, photoallergic, phototoxic]). Environmental factors, such as irritants, allergens and stress, can aggravate endogenous forms of dermatitis. Even if no cause is identified, the rash can often be treated successfully.

For information on the different types of dermatitis, see:

See also lichen simplex, nodular prurigo and nappy rash.