We tested 227 patients with dermatoses and dry skin who presented to a dermatologist for the presence of mutations in the filaggrin gene (FLG): R501X (rs61816761), 2282del4 (rs558269137), R2447X (rs138726443). R2447X mutation was found in 2 (0.9%) brothers, 2282del4 was found in 19.8% of patients, R501X was not detected in any patient. There were 109 patients with atopic dermatitis (AD) in the group, dry skin was noted in all patients. But mutations in the FLG gene were found in only 28% of patients: of 18 homozygotes with the 2282del4 mutation, 11 had Ad; of 27 heterozygotes with this mutation, 18 had AD, and both patients heterozygous for the R2447X mutation had AD. The prevalence of the rs558269157 minor allele for all patients with clinically dry skin was 14%, for AD, it was 15%, for the combination of AD with ichthyosis, it was 50%, and for ichthyosis, it was 71%. Assessment of clinical severity of AD by SCORAD showed that in the homozygous 2282del4 mutation group, SCORAD was 43.8 (34.6; 48.0), heterozygotes — 26.5 (19.7; 30.8), in 2 patients heterozygous for the R2447X mutation during exacerbation SCORAD reached 60, and in patients, without the mutation, it was 23.4 (21.6; 25.8). After topical therapy (for one month), there was an improvement in all groups, except for three patients with a severe course, for whom systemic therapy was planned from the beginning; topical therapy was prescribed to them at the preliminary stage. Patients with ichthyosis and AD predominated among patients with a mutation in the FLG gene, but several dermatoses (vitiligo, widespread seborrheic keratosis, follicular hyperkeratosis) were also reported more frequently than in patients without the mutation, which requires further follow-up.