Ichthyosis

The goal of this observational study is to conduct a prospective assessment of the individual Burden of 9 rare skin diseases to assess disability in the broadest sense of the term (psychological, social, economic and physical) for patients and/or families. Two types of indicators will be used to reach this objective : 1. an individual burden score calculated based on a burden questionnaire created specifically, approved and designed to understand the tendency to changes in care and lifestyles. The burden questionnaire should be used by patients and/or their family themselves in self-assessment. 2. a descriptive analysis of all resources (medical and non-medical) used by the family unit to manage the disease.