Antineutrophil Cytoplasmic Antibody-Associated Vasculitis in a Pediatric Patient Presenting With Hemoptysis

This case report discusses a rare pediatric case of granulomatosis with polyangiitis (GPA) presenting with hemoptysis, migratory polyarthralgia, significant laboratory abnormalities, and imaging findings. GPA is a form of vasculitis that primarily affects the upper and lower respiratory tracts and the kidneys. Pediatric cases, though rare, offer a distinct set of clinical challenges. The patient presented to the emergency department with hemoptysis, joint pain, and cough. Radiologic findings included diffuse bilateral nodular airspace opacities on chest X-ray (CXR) and ground glass opacities on computed tomography (CT). After hospital admission, the patient's bronchoscopy suggested diffuse alveolar hemorrhage. Laboratory tests were positive for proteinase 3 (PR3), indicating a possible diagnosis of GPA. Further tests, consultations, and evaluations corroborated this diagnosis. Treatment administered included high-dose intravenous steroids, rituximab, and other supportive measures. Pediatric GPA, while rare, is a challenging diagnostic entity. A comprehensive and multidisciplinary approach is pivotal for timely diagnosis and initiation of appropriate therapy.