ABSTRACT
This chapter focuses on histomorphology. It considers the pathophysiology and provides an abbreviated synopsis of the salient clinical features of eczema. The histomorphological spectrum of eczema is best considered in the context of the clinical phases of allergic contact dermatitis. Erythroderma manifests as a dermatitis which may be acute, subacute, or chronic/psoriasiform. Children may manifest a hypopigmented scaly macular dermatitis termed ‘pityriasis alba’ in which depigmentation of the skin through postinflammatory pigment loss results in pale discoloration. Chronic, superficial, persistent dermatitis or small-plaque parapsoriasis is considered with the spongiotic dermatitides. Dyshidrotic eczema or pompholyx is held by some observers to be merely a form of contact dermatitis of the hands and soles comprising tense vesicles, often affecting the sides of the digits, the palms, or the soles. Miliaria rubra or prickly heat rash produces 1-to-2 mm erythematous papules and vesicles on the trunk and groin associated with a prickly sensation.
