Use of indomethacin in Langerhans cell histiocytosis

BACKGROUND: Because prostaglandin (PG) E2 has been identified in the bone lesions of Langerhans cell histiocytosis (LCH), we speculated that indomethacin, a potent PG inhibitor, may be useful in patients with symptomatic LCH involving the bony skeleton. PROCEDURE: We used indomethacin to treat patients in whom we wanted to avoid steroids or chemotherapy, or in whom these treatments did not provide complete symptom relief. Ten children with bony LCH between 1984 and 1995 were treated; six had single-system bone disease and four had multisystem disease involving the bony skeleton and other organs. RESULTS: The dose of indomethacin ranged from 1 to 2.5 mg/kg/day (9-200 mg/day) in divided doses and was given for 1-16 weeks (mean, 6 weeks). Eight patients had a complete response to treatment, defined as complete resolution of symptoms for 4 weeks. One patient was withdrawn from treatment because of concern regarding the potential of indomethacin to induce seizures and a second patient, with suppurative skin lesions overlying a lytic skull defect, did not respond. CONCLUSIONS: Indomethacin is a useful therapy for LCH involving the bony skeleton and may have a role as first-line treatment in single-system bone disease. Whether it has a specific role in slowing disease progression or merely acts as an analgesic has not yet been established.