Familial cold urticaria (FCAS) is the mildest form of cryopyrin-associated periodic syndrome (CAPS; see this term) and is characterized by recurrent episodes of urticaria-like skin rash triggered by exposure to cold associated with low-grade fever, general malaise, eye redness and arthralgia/myalgia. The disease is Orphanet_47045 (Familial cold urticaria). Also known as: FCAS, FCAS1, FCU, Familial cold autoinflammatory syndrome.