Clinical features of various phenotypes of atopic dermatitis

Genetic predisposition, twophase immune response, T1 and T2 lymphocytes dysbalance, epidermal barrier dysfunction, trigger factors, antigens play an important role in the atopic dermatitis pathogenesis. Recently, genotypes, phenotypes of the disease, as well as the relationship of genetic factors, pathogenesis and clinical features of AD, which determine the phenotype of the disease, are actively studied. The purpose of this research was to evaluate the clinical features of different AD phenotypes. Materials and methods. The research was conducted as an open prospective study. 86 patients suffered from moderate and severe AD, including 25 children aged 2 to 18 years and 61 adults aged 19 to 54 years were involved. Patients in the skin allergy and immunopathology department of «The Institute of Immunology of the FMBA of Russia» in the period from 2012 to 2016 were observed. The followup period was at least 1 year. The inclusion criteria of this group were the ability to collect a full anamnesis, the allergological examination, assessment of the severity of the disease and the response to the therapy, the adequacy of the fulfilment of the doctor’s recommendations by the patients, including compliance with elimination measures, diet, rational skin care, as well as the use of topical treatment. All patients received standard therapy according to Russian and international clinical guidelines. The severity of the disease was assessed on the basis of SCORAD and IGA scales, effectiveness of topical treatment and adverse events frequency. Results. The main criteria for determining of AD clinical phenotypes were established: severity of the disease (based on SCORAD, IGA); frequency and duration of exacerbations; age of onset of the disease; secondary skin infection; concomitant respiratory allergic diseases and sensitization to different groups of allergens; resistance to therapy. Recurrent course of AD and resistance to standard topical corticosteroids therapy were observed in 8 (32%) children and in 20 (32.7%) adults. The results of examination of representative sample of patients allowed to identify and characterize several AD phenotypes: isolated uncomplicated AD - in 15% of patients; AD complicated by secondary infection and the presence of sensitization to bacterial or fungal allergens - in 7% of patients; AD accompanied by the concomitant respiratory allergic diseases and the presence of sensitization to food and respiratory allergens - in 29% of patients; extremely severe AD, accompanied by secondary infection, respiratory allergic diseases and polyvalent sensitization, resistance to therapy - in 36% of patients. Conclusion. Identification of the clinical phenotype allows to determine the patients on the grounds of the clinical characteristics and AD features, which can be useful for understanding the etiopathogenesis of the disease in a particular patient and can be the basis for development of personalized approaches to the diagnosis and treatment of AD.

atopic dermatitis, phenotypes, resistance to therapy