Case report of streptococcal infection as a potential precipitating factor in cutaneous polyarteritis nodosa in pediatric patients.

Key Clinical Message: This pediatric case report underscores the importance of maintaining a high clinical suspicion for polyarteritis nodosa (PAN) in patients presenting with atypical features, such as migratory arthritis and subcutaneous nodules. Importantly, it highlights the focus on the potential relationship between streptococcal infection and cutaneous PAN. Early recognition and prompt, aggressive treatment is critical, as PAN can be a life-threatening condition if left unmanaged. This case emphasizes the need for a multidisciplinary approach to effectively identify and manage this rare vasculitis disorder in the pediatric population. Abstract: Polyarteritis nodosa (PAN) is a rare and life-threatening vasculitis with diverse clinical presentations, posing a diagnostic challenge. Early recognition and prompt intervention are crucial to prevent organ damage. We present the case of an 8-year-old boy who exhibited atypical symptoms including migratory arthritis, myalgia, digital discoloration and ischemic changes, and subcutaneous nodules. Initial concerns for septic arthritis were ruled out. A comprehensive evaluation revealed elevated inflammatory markers and a confirmatory skin biopsy demonstrating active leukocytoclastic vasculitis, are highly suggestive of a diagnosis of PAN. Notably, elevated ASO titers suggested a possible concurrent streptococcal infection. The aggressive treatment approach with high-dose aspirin, steroids, methotrexate, and tocilizumab is justified given the severity of the patient's symptoms and the nature of the disease process. This case underscores the importance of considering PAN in the differential diagnosis for children presenting with atypical features. Early diagnosis and prompt intervention, including addressing potential infectious triggers, are crucial for optimal outcomes in pediatric PAN.