Diagnosis of Erdheim–Chester disease following the workup of multiple falls

the abdomen and limbs and massive weight loss. Physical examination noted a limited abduction of shoulders and irreducible flexion contracture of knees and elbows. Laboratory tests revealed eosinophilia at 1700 E/mm and hypergammaglobulinemia. A deep tissue biopsy noted a dermal thickening and fibrosis with perivascular nonspecific inflammatory infiltration, a fibrotic fascia with abundant infiltration by lymphocytes, plasma cells and numerous eosinophils. Muscular specimen shows no abnormalities. Magnetic resonance imaging showed fasciitis involving the different muscular compartments of the thigh predominant in the posterior compartment associated to muscular atrophy without significant anomalies of intra-muscular or subcutaneous fat signal intensity. Our two patients were treated with prednisone (1mg/kg/day) and physical therapy with insufficient response. Methotrexate was associated at 10 mg/week in addition to prolonged physical rehabilitation. The follow-upwasmarked by partial improvement of skin induration and joint stiffness. Case report 2: A 15 year old girl with a history of Hashimoto diseasewas seen for painless thickening of legs and forearms skinwith joint stiffness and proximalmuscular deficit. Physical examination noted also flexion contractures of the fingers and muscular atrophy of triceps and quadriceps. Laboratory testing revealed a peripheral eosinophilia at 1100 E/mm, hypergammaglobulinemia, anemia and inflammatory biologic syndrome. Muscular enzymes were at normal level. A deep tissue biopsy revealed subcutaneous nonspecific inflammatory infiltration with fibrosis of the derma. Muscular biopsy showed a nonspecificmyositis. Magnetic resonance imaging redescribed myositis involving pelvic muscles and fasciitis of the muscular lodges at the thigh backside. The evolution was characterized by a steroid's resistance indicating the association of methotrexate (12 mg per week). Conclusion: Eosinophilic fasciitis is an uncommon disease in childhood that must be considered in any patient with skin induration and painless joint contractures. The majority of patients are steroid responsive, but recourse to more aggressive treatment may be necessary. Interdisciplinary approach, including physical therapy, is crucial to prevent long-term morbidity.