Inclusion Criteria:  The subject has signed an informed consent; parental or legal representative consent for patients under 18 years of age, as well as additional consent for patients aged ≥ 15 and <18.  At the time of participation in the study, the age of the subject is not less than 6 months and not more than 18 years. At the time of participation in the study, a clinical diagnosis was established: Congenital ichthyosis with various clinical forms, with the exception of vulgar and X - linked congenital ichthyosis (genetic research is not a prerequisite for participation in the study). Subjects should have at least moderate IASI erythema associated with his / her ichthyosis, and a decrease in the quality of life according to CDLQI ≥ 10 Absence of signs of severe infectious diseases (pneumonia, tuberculosis, etc.) No previous history of the use of the following genetically engineered biological drugs: ustekinumab, secukinumab, dupilumab  Exclusion Criteria:  Subjects who have an allergic reaction to ustekinumab, secukinumab or other components of the drugs. Subjects who have bacterial and/or fungal diseases. Subjects who have problems in dynamic observation. Subjects who will have a worsening of clinical symptoms