Henoch-Schonlein Purpura with Lumbar Pain and Swelling as the Unusual Presentation in a 6-Year-Old Girl

Introduction: Henoch-Schonlein purpura (HSP) is the most common vasculitis in children, often following an upper respiratory tract infection. The classic tetrad of symptoms and signs includes palpable purpura (mandatory criterion), arthralgias, abdominal pain, and renal involvement. Other clinical findings, such as subcutaneous edema in the hands, ankles, and feet, are quite common in pediatric HSP. However, lumbar edema is a rare and atypical manifestation, with very few cases reported worldwide. Case Presentation: A 6-year-old girl was admitted to the pediatric ward with severe lumbar pain and swelling, along with leg pain, without a history of trauma. On initial examination, she had severe edema and tenderness of the back and a limited number of petechiae and purpura in the lower extremities. During hospitalization, the patient developed edema in her right ankle. She was clinically diagnosed with HSP. Conclusions: Lumbar involvement is a rare manifestation of HSP. During the literature review, only seven cases of HSP with lumbar edema were identified. Recognizing the rare and atypical manifestations of this disease can be helpful in its early diagnosis, especially in patients who have a delayed onset of the typical rash of the disease.