Exploring the Diagnostic Odyssey of IgA Vasculitis.

IgA vasculitis is a form of small vessel vasculitis characterized by IgA immune complex deposition. Although primarily affecting children, it can also occur in adults, often with more severe manifestations and a higher risk of chronic kidney disease (CKD). The authors present the case of a 77-year-old man with significant cardiovascular risk and atrial fibrillation who was admitted to the emergency department (ED) with pruritic and painful palpable purpuric rash, weight loss, and asthenia persisting for approximately one month prior to presentation. Laboratory findings revealed normocytic normochromic anemia, worsening renal function, elevated inflammatory markers, and leukoerythrocyturia. Initially diagnosed as infectious purpura associated with urinary tract infection, the patient was discharged with a prescription for antibiotics (cefixime). Subsequent worsening of the skin lesions, constitutional symptoms, and gross hematuria prompted a second visit to the ED, and the persistent deterioration of kidney function and inflammatory parameters led to admission for further investigation and consideration of a kidney biopsy. This case report describes the etiological investigation, providing a brief review of the typical characteristics of this disease and highlighting the importance of certain factors in establishing the diagnosis, notably the need and timing of a biopsy of the affected organ for a definitive diagnosis. Additionally, the clinical case underscores the diagnostic challenge, particularly when histological confirmation is elusive.