Eczema/dermatitis is a type of polymorphic inflammatory reaction pattern involving the epidermis and dermis which may be provoked by a number of external or internal factors and can be defined histologically by spongiosis and interstitial vesicles.
Acute eczema: it is an erythema and edema in plaques, usually with ill-defined borders. Afterwards pruritic vesicles, exudation, crusting and finally scaling. The resolution is without scars.
Chronic eczema: it is less vesicular and exudative, more scaly, pigmented and thickened, more likely to develop painful fissures and to be lichenified.