[Cryopyrine-associated periodic syndrome: CAPS seen from adulthood]

Cryopyrin-associated periodic syndrome is a rare hereditary periodic fever syndrome for which, the genetic mechanism, mutation in the NLRP3 gene, has allowed to gather 3 clinical phenotypes (familial cold urticaria [FCAS], Muckle-Wells syndrome [MWS], and chronic infantile neurological cutaneous and articular syndrome [CINCA]) initially described independently, and to discover the NLRP3 inflammasome, a key receptor of the innate immunity, which regulates the interleukine-1β secretion into the mononuclear cells. The clinical manifestation of CAPS : urticaria-like skin rash, eyes redness, myalgia and sensory deafness are not specific, if considered separately, and that often leads to a wandering diagnosis through a complex medical journey including various specialists. The diagnostic delay is deleterious to patients compromising their quality of life and exposing them to neurosensory complications and renal failure by secondary amyloidosis. The paediatric onset of disease, the family history, the trigger of symptoms by the cold, and the recognition of the skin rash as neutrophilic are important clues before diagnostic confirmation by genetic testing. Interleukine-1 blockade is the only effective treatment of CAPS symptoms which often may stabilize (rarely regression) the sensory involvement and in some cases may allow the regression of secondary amyloidosis.