Reactivation of Hand-Schüller-Christian disease six and thirteen years after discontinuation of systemic therapy.

We present two cases of reactivation of Hand-Schüller-Christian disease or multifocal eosinophilic granuloma 6 and 13 years after discontinuation of systemic therapy. Both patients received oral therapy with methotrexate and prednisone continuing for 2--3 years after the disease was thought to be in remission. Relapses were detected because of disease symptoms and treated with surgery with or without radiation. Neither patient has required reinstitution of systemic therapy. These cases are cited as evidence of the chronicity of the disorder and as a reminder that reactivation is possible after years of disease inactivity. Therefore, long-term clinical follow-up of patients in remission is indicated.