Pediatric Granulomatosis With Polyangiitis: A Case Report Compared to a Case Review in the Last 10 Years.

Granulomatosis with polyangiitis (GPA), previously described as Wegener's granulomatosis, is a rare autoimmune disease that causes necrotizing systemic vasculitis, affecting small- and medium-sized blood vessels. While adults typically receive GPA diagnoses more frequently, children and adolescents can also experience it, albeit infrequently. In pediatric patients, the disease presents challenges due to its rarity and complex clinical symptoms. Early detection and treatment are essential for minimizing long-term complications and improving outcomes. We conducted a literature review that included cases of GPA in children reported between 2014 and 2024, focusing on their unique clinical presentation and outcomes. In this report, we present a seven-year-old girl characterized by an atypical clinical course that included neurological manifestations, particularly posterior reversible encephalopathy syndrome (PRES) and rapidly progressive glomerulonephritis, resulting in end-stage kidney disease, which required hemodialysis. After analyzing all the data, we found that the patient had been diagnosed with GPA. Clinical symptoms are similar to those reported in the literature. These symptoms include female sex and constitutional symptoms (fever, weight loss, fatigue), arthralgia, and multiple organ involvement (hemoptysis, an image demonstrating pulmonary nodules and peribronchovascular infiltrates), as well as otorhinolaryngological symptoms (including nasal crusting and rhinitis history), along with renal impairment (proteinuria, hematuria, and glomerulonephritis pattern). Our case differs from others in the literature due to its early onset (the average age at diagnosis in the recent research was 12 years old), the patient's poor response to cyclophosphamide (CYC) treatment (she developed right lower and middle lobe pneumonia and hemoptysis), and the unexpected changes in her symptoms. She experienced several paroxysmal events, including confusion, blurred vision, generalized seizures with tonic-clonic movements, and deviation of her eyes to the right side, which was followed by temporary aphasia. These neurological symptoms prompted us to conduct a more thorough investigation, leading us to identify a homozygote mutation C667T in the methylenetetrahydrofolate reductase gene (MTHFR). This case highlights the importance of a high index of suspicion for GPS in patients with constitutional symptoms (fever, weight loss, fatigue), arthralgia, and multiple organ involvement, as well as early detection and timely treatment.