Numerous nomenclatures and classifications of eczemas have puzzled dermatologists for a long time. This confusion is due to the great number of external as well as internal noxious factors and/or agents causing eczemas being themselves a distinct and histologically well defined reaction of the papillary-epidermal compartment. Current classifications do not adequately reflect the complex causative conditions involved in the etiopathogenesis of eczematous disorders. I propose, therefore, to classify eczematous disorders according to the following three principal categories: "mainly endogenous" (or "atopic") eczemas, "mainly exogenous" (or "contact") eczemas, and "dysregulatory microbial" eczemas. The latter group comprises eczemas caused by various kinds of functional derangement of epidermal protective properties (e.g., venous stasis, exsiccation of horny layer, seborrhea/hyperhidrosis, epidermal atrophy), which in turn permit the resident and/or transient microflora of the horny layer to induce inflammatory responses of eczematous pattern. Since morphological, topical, and other clinical attributes may change in the course of the very same eczematous disease, they are inappropriate for basic classification of eczemas and should be only employed as minor criteria to characterize the predominant "type" or subset (i.e., clinical appearance) of the specific eczema. The possible combination of eczemas representing two (or even three) categories in one patient leads to intermediate forms entirely in keeping with the division into three principal groups. The classification proposed is aimed at eliminating the terminological confusion as well as enabling reliable documentation for compatible statistics, and should consequently improve the sematic communication between dermatologists and other physicians.