This paper provides a review of modern studies of the etiology of torpid forms of atopic dermatitis (AtD) and the results of the authors’ own research. The authors propose the following algorithm for identification of the AtD etiology in a particular patient with torpid AtD: 1) the use of the clinical genealogical method (examining the proband and relatives, preparing the genealogy, listing diseases to be checked by differential diagnostics, and listing examinations for the proband and relatives); 2) exclusion/confirmation of carrying frequent mutations in the filaggrin gene (FLG); 3) exclusion/confirmation of metabolic disorder or nutritional disorder by a chromographic urine test (in children under 5 years); 4) exclusion/confirmation of the glutensensitivity by a test for gliadin antibodies; 5) a karyological test (in the presence of specific phenotypic signs). If there are indications, FISH or CGH array should be conducted. The use of the algorithm enables identification of the AtD etiology in a significant part of patients with a torpid form of the disease and administration of etiotropic and/or pathogenetically appropriate therapy.