Treatment with systemic corticosteroids led to the control of hematuria, but as nephrotic-range proteinuria persisted, cyclophosphamide was added, leading to a gradual decrease in proteinuria.<h4>Conclusions</h4>We propose an underlying common mechanism in the pathogenesis of both HSP and psoriasis, involving a dysregulation of the IgA-mediated immune response, which could predispose to both entities as well as to kidney damage and IgA nephropathy in these patients. The gene discussed is CD79A; the disease is psoriasis.