It may initially be restricted to the skin around the malleoli of the ankle, but usually extends to the dorsal surface of the legs, the buttocks and ulnar site of the arms. In children younger than three years the clinical picture may be dominated by edema of the scalp, the periorbital area, the hands and the feet. The edema correlates with the activity of the vasculitis and not with the degree of proteinuria. It has also been attributed to the enteric loss of protein. There is no frank arthritis and joint effusions are rare.
Hematemesis occurs less frequently.
While the whole clinical spectrum of glomerulonephritis may occur in HSP, hematuria with mild or moderate proteinuria is the most common presentation. The glomerular changes in HSP have been studied extensively. They may show a wide spectrum, ranging from very mild changes to severe lesions. Most glomeruli may look normal by light microscopy with only a few showing mesangial proliferation. Other cases may show focal and segmental intracapillary and extra capillary proliferation with adhesions in small crescents.