What is Eczema?

Eczema, also known as dermatitis, is a reaction pattern that presents with variable clinical and histological findings. It is the final common expression for a number of disorders which includes atopic dermatitis, allergic contact and irritant contact dermatitis, dyshidrotic eczema, nummular eczema, lichen simplex chronicus, asteatotic eczema, and seborrheic dermatitis. Primary lesions, which include papules, erythematous macules, and vesicles, can coalesce to form patches and plaques. Secondary lesions from infection or excoriation, marked by weeping and crusting, may predominate in severe eczema. Long-standing dermatitis is often dry and is characterized by thickened, scaling skin.