Study of Skin and Gut Microbiome in a Skin Condition Involving Skin Barrier Impairment and Allergic Symptoms: Netherton Syndrome

It is proposed to conduct an exploratory study to analyze the skin, intestinal, and salivary microbiome, as well as the skin mycobiome and virome, of patients (adolescents and young adults) with Netherton syndrome, a condition characterized by an impaired skin barrier that most likely promotes the development of allergic manifestations. The study will be conducted on patients with Netherton syndrome and control subjects in order to investigate possible correlation factors between the three microbiomes and identify which ones.

Inclusion Criteria: Group A: * Children aged 10 years and older and adults with confirmed Netherton syndrome diagnosed at age 10 years or older (clinical and histological and/or molecular) * Patients and legal guardians informed about the study and not opposed to participation in the study Group B: * Children aged 10 years and older and adults with no skin barrier impairment, dermatosis, inflammatory disease, or autoimmune disease. * Subjects and legal guardians informed about the study and who do not object to participation in the study. Exclusion Criteria: * Refusal by parents/guardians, children, adolescents, or adults. * General or local antibiotic therapy within the month preceding the consultation.