Uncommon clinical pattern of FMF: protracted febrile myalgia syndrome

Familial Mediterranean fever (FMF) is a genetic multisystem disorder of unknown etiology characterized by recurrent episodes of fever and pain due to acute inflammation of the peritoneum, synovia, or pleura. Up to 25% of patients with FMF report muscle pain. Myalgia may be a spontaneous pattern, exercise-induced pattern, or protracted febrile myalgia syndrome (PFMS). PFMS is characterized by severe paralyzing myalgia, high fever, abdominal pain, diarrhea, arthritis/arthralgia, and transient vasculitic rashes mimicking Henoch-Schonlein purpura. The episodes last for 4-6 weeks, except in those patients treated with corticosteroids. The PFMS may recur even under colchicine prophylaxis. We describe a 30-year-old pregnant Turkish woman with known FMF and under colchicine prophylaxis, with severe myalgia for 8 weeks, emphasizing the importance of a different clinical pattern of PFMS even in the absence of other symptoms.