<prompt> A 8-year-old male had non-blanching rashes over the shin and swelling of the knee joint with haematuria and protein . Microscopic analysis of his renal biopsy specimen is most likely to showTubular necrosisVisceral podocyte fusionMesangial deposits of IgABasement membrane thickening  <response>: This child has i Rash ii Arthritis swelling of knee joint iii HaematuriaAll these suggest the diagnosis of Henoch Schonlein purpuraHSP is characterized by deposition of IgA in the mesangium. 