A 14-week-old girl was brought in with a history of painful swelling of both legs since the age of one month. The onset was insidious and was not associated with trauma or fall. There was no history of fever or associated constitutional symptoms. The birth history was normal and the infant was apparently asymptomatic until the age of one month. Examination revealed a healthy and alert infant. Both legs were bowed anteriorly and a uniform bony thickening of both tibiae was palpable throughout their lengths (figure 1). Both legs were extremely tender and the infant would withdraw both lower limbs and cry incessantly if any attempt was made to touch them. There was no increase in local temperature nor redness of the overlying skin. Knees and ankle joints were normal and demonstrated a full range of motion. Regional lymph nodes were not enlarged and other bones and joints were normal on examination. X-Rays of both legs revealed peri-osteitis of both tibiae with extensive subperiosteal new bone formation involving the entire diaphysis (figure 2).