When Urticaria Is Not Just an Allergy: A Case of IgA Vasculitis Masquerading as a Drug Reaction

Immunoglobulin A (IgA) vasculitis previously called Henoch-Schönlein Purpura represents the most common vasculitis of childhood, characterized by IgA1 deposition in small vessels of the skin, joints, gastrointestinal (GI) tract, and kidney (1). This case report presents an atypical presentation of IgA vasculitis in an eight-year-old girl, where the skin manifestations were predominated by urticarial rashes prior to the onset of the classical palpable purpura and was mistaken as a case of drug induced urticaria. She presented with an acute history of severe pain abdomen, urticarial rashes over buttocks, bilateral knee joint pain and difficulty in walking with burning sensation of both feet. She was being treated as a case of acute gastroenteritis with drug induced urticaria prior to presentation at our center. On detailed physical examination bilateral lower limb palpable purpura were noticed with prolonged capillary refill time in bilateral toes and feeble dorsalis pedis pulses. The diagnosis of IgA vasculitis was made clinically based on EULAR criteria, and she was treated with steroids and supportive management on which patient recovered well and remained asymptomatic during follow up. This case highlights the importance of considering a diagnosis of IgA vasculitis in children with atypical presentation like in our case where urticarial rashes preceded the classical palpable lower limb purpura. The multisystem presentation of disease with nonspecific symptoms and lack of definitive diagnostic tests, mandates a high index of suspicion in these children. Although the illness can be self-limiting, but the potential for late renal involvement and end-stage renal disease underscores the importance of early diagnosis and treatment.