Atopic dermatitis, eczema, allergic dermatitis occupy the main place among dermatoses, where the allergic component is leading in the onset and development of the disease. The most common complication of allergic dermatitis is the attachment of a secondary pyococcus infection, which is associated with a decrease in the antimicrobial resistance of the skin surface. Therapy of infectious lesions is complicated by the increasing resistance of the main pathogens of pyoderma - Staphylococcus aureus and Staphylococcus epidermidis - to widely used antibiotics.The aim of the research: to determine the phenotypic features of staphylococci extracted from patients with allergic dermatitis to assess their pathogenic potential.Materials and methods. The object of the study was 369 staphylococcus isolates removed from affected and intact skin sections of patients with allergic dermatitis, as well as from representative skin sections of healthy individuals undergoing inpatient treatment at the Department of Dermatology of “Institute of Dermatology and Venereology of NAMS of Ukraine”. Biochemical identification and biological properties of staphylococci were determined using methods of classical bacteriology.Results. As a result of the conducted researches, it is established that the complex of phenotypic traits of the removed staphylococcus cultures indicates the presence in the pathogen of factors related to the resistance of the host protection mechanisms and determines the intensity of the alterative action of the infectant in relation to the host organism, the phenotypic manifestation of the studied factors was higher in the staphylococcus isolates removed from the affected skin areas of patients with allergic dermatitis. Conclusions. The level and frequency of phenotypic expression of pathogenicity factors are more pronounced in microorganisms obtained from patients from affected and intact areas compared to controls, which confirms their pathogenetic role in the burden of the disease, which in turn can be used as an auxiliary differential diagnosis criterion.