You are correct. Bx of skin and kidneys confirmed the dx of immunoglobulin A vasculitis, previously known as Henoch-Schönlein purpura. IgA vasculitis is a systemic small vasculitis that features palpable purpura, renal damage, joint pain (80%), and abdominal pain (70%). URIs often precede sx onset by 1 to 2 weeks. IgA vasculitis is characterized by IgA deposition in postcapillary venules, accompanied by leukocytoclasis. Absence of fever and systemic toxicity made meningococcal infection unlikely, and platelets are low in thrombocytopenia.

The patient was treated with prednisone 40 mg daily. After a week, the cutaneous purpura, abdominal pain, and arthralgias improved substantially, and a stool test showed no red blood cells. UA was negative after 4 weeks.

BMJ 2021;372:n329