[A case of IgA nephropathy associated with psoriasis vulgaris].

Nephrotic syndrome due to IgA nephropathy was found in a 45-year-old man with psoriasis vulgaris. He was first diagnosed as psoriasis vulgaris at 20 years age and had exhibited proteinuria since 37 years of age. Recently, he developed nephrotic syndrome with unfavorable progression of psoriasis. The conditions of psoriasis and nephrotic syndrome were consistently parallel, and both diseases responded to corticosteroid therapy. The specimens from renal biopsy showed mesangial proliferative glomerulonephritis and sclerosis with mesangial deposition of IgA. Therefore, we diagnosed this case as IgA nephropathy. Twelve cases with chronic glomerulonephritis associated with psoriasis vulgaris have been published. All biopsied specimens from these cases showed mesangial deposition of IgA. Immune abnormalities have been reported in both diseases. The pathogenesis of psoriasis vulgaris and IgA nephropathy may be related through an immune mechanism.