Soft tissue and bony enlargement of the mandible in an infant

An 8-week, full-term infant, with an uncomplicated delivery, presented to Childrens’ Mercy Hospital with a 3-day history of fever, irritability, and constipation. The mother had noted swelling over the right mandible and became concerned. On admission to the hospital, it was noted that the child was lethargic, but did not appear to be in any pain. The rectal temperature was lOl”F, the white blood cell count was 21,4OO/pL, hemoglobin was 10.6 g, the platelet count was 1.1 million, the sedimentation rate was 62 mm/h, and alkaline phosphatase was 466 IU. Radiographs revealed soft tissue enlargement over the right mandible, which was also enlarged (Fig 1). Periosteal enlargement of the right ribs and a pleural effusion were also noted (Fig 2). There was no involvement of the ulna or tibia. A growth chart comparison revealed a substantial drop from the 50th percentile to the 5th percentile, with no reported change in diet or stools.