This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Pediatrics
A 7-year-old boy presents with palpable non-blanching rash starting 3 days back from the ankles and involves lower limbs and buttocks. He had viral URTI previously. BP is normal and KFT is normal. What is the diagnosis? 
Select and explain. 
A. Henoch-Schonlein purpura, B. Meningococcemia, C. Hemolytic uremic syndrome, D. Cutis marmorata
A: Henoch-Schonlein purpura
Answer: A: Henoch-Schonlein purpura 
Explanation: Ans. (a) Henoch-Schonlein purpura.* The presence of normal KFT and normal BP means GFR is unaffected. With purpura involving the ankles, lower limbs following a URTI, IgA deposition in dermal blood vessels indicates the presence of Henoch-schonlein purpura.* Hemolytic uremic syndrome is ruled out due to normal KFT.Image source. style="font-size: 1.04761904761905em; color: rgba(0, 0, 0, 1); font-family: Times New Roman, Times, serif; margin: 0 0 8pt">