Successful Induction Treatment With Rituximab of Isolated Pauci-Immune Pulmonary Capillaritis Presenting as Diffuse Alveolar Hemorrhage in a Pediatric Patient.

Diffuse alveolar hemorrhage often presents as dyspnea, cough, or hemoptysis, and it is mediated by both immune and nonimmune processes. Isolated pauci-immune capillaritis (IPPC) is a rare diagnosis in which capillaritis, small-vessel vasculitis of the lung, is found on biopsy in the absence of an underlying systemic disorder. Traditionally, IPPC has been treated similarly to anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis with cyclophosphamide and glucocorticoids. However, few cases describing management options are available in the literature, especially among pediatric patients. Our report of successful induction of remission in an adolescent girl suggests that the combination of IV rituximab and pulse methylprednisolone may be a viable option for disease control in pediatric patients with IPPC.