Levamisole-induced anti-neutrophil cytoplasmic antibodies-associated vasculitis in paediatric nephrotic syndrome: dose-dependent and idiosyncratic risks in paediatric patients.

Levamisole, a synthetic imidazothiazole derivative, remains a cornerstone in the management of frequently relapsing nephrotic syndrome and steroid-dependent nephrotic syndrome in resource-limited settings. While its efficacy as a steroid-sparing agent is well-established, its safety profile is complicated by rare but severe autoimmune phenomena. We present two distinct paediatric cases of levamisole-induced vasculitis from India.The first case involves a female child in middle childhood who developed multisystemic vasculitis (pulmonary, renal and cutaneous) following an accidental dose escalation. The second involves a female child, also in middle childhood, who developed a similar phenotype after prolonged, stable therapy. Both cases were marked by the presence of anti-neutrophil cytoplasmic antibody and resolved promptly on drug withdrawal. These cases underscore that levamisole-induced autoimmunity is not confined to specific ethnicities or illicit drug contaminants but is a direct iatrogenic risk that clinicians must monitor closely in the paediatric population.