Familial cold urticaria (FCAS) is the mildest form of cryopyrin-associated periodic syndrome (CAPS) 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 MONDO_0018768 (familial cold autoinflammatory syndrome). Also known as: FCAS, FCU.