Diagnosis, Determining Factors, and Characteristics of Pathologies Associated With Autoinflammatory Diseases.

Autoinflammatory diseases are part of a heterogeneous group of diseases that manifest themselves through an inflammatory reaction in their initial phase (innate immunity) that is activated inappropriately: either because the reaction is too strong or because it is unjustified (for example, in the absence of infection). In many cases, and in their initial description, autoinflammatory diseases have a genetic origin (and are therefore hereditary or familial) and preferentially affect children or young adults. However, a significant number of other diseases have expanded this nosological field due to the preponderance of autoinflammation in explaining the symptoms. Sometimes, autoinflammatory disease can also remain "unclassified." In general, autoinflammatory diseases manifest as recurrent attacks combining fever, skin rashes, and joint pain. Certain signs are more specific to certain diseases, such as hives, abdominal pain, mouth ulcers, or swollen lymph nodes in the neck. It is mainly the recurrence of attacks and their unprovoked nature that attract the attention of the patient and the doctor. These attacks are systematically associated with an increase in inflammatory markers in the blood. Currently, most autoinflammatory diseases are diagnosed based on a combination of clinical and biological evidence, following a thorough investigation by specialists in these diseases. Biological markers that can confirm the disease are rare. However, for some of them, confirmation can be obtained through genetic analysis. In certain cases, extensive genetic analysis may be offered. Autoinflammatory diseases are managed by specialists (internists, rheumatologists, etc.) in close collaboration with primary care physicians and other healthcare professionals (nurses, physical therapists, social workers, etc.). Treatment is sometimes based on exceptional drugs that can only be prescribed and dispensed in hospitals. This multicenter, national study, which targets children and adults with rare autoinflammatory diseases, aims to identify: * the "key" parameters for a faster diagnosis, * the determining factors and their associated characteristics, and * the treatments used and their effectiveness.