To study the frequency and clinical patterns of myalgia in a defined group of children with familial Mediterranean fever (FMF).
A prospective 4-year (September 1995-September 1999) study of children with FMF seen in the pediatric FMF clinic of Jordan University teaching hospital. Diagnosis of FMF was made according to published criteria. Once the diagnosis of FMF and myalgia was made, details about myalgia were collected by interview with the child and his/her parents and entered into a special study form.
Of 264 children with FMF seen over the study period, 65 (25%) developed myalgia. Three clinical patterns of myalgia were identified: the spontaneous pattern, the exercise-induced pattern, and the protracted febrile myalgia syndrome (PFMS), seen in 8%, 81%, and 11% of patients, respectively. The three patterns differed in the severity of pain, height of fever, and duration of the episode. In 33 children with the exercise-induced myalgia, in which response to colchicine could be reliably assessed, a favorable response was achieved in 97%. Three children with the PFMS had a dramatic response to corticosteroids.
Myalgia in children with FMF is common and can follow three different clinical patterns.