Psoriatic nephropathy--does an entity exist?

Psoriasis is an immune-mediated chronic inflammatory disorder of the skin. Association with kidney disease has been debated for a long time. Secondary renal amyloidosis in psoriatic arthropathy and drug-induced renal lesions secondary to methotrexate or cyclosporine are accepted accompaniments of psoriasis. IgA nephropathy is also known to occur in psoriatics. We report three interesting cases of renal involvement in long-standing established psoriasis on topical therapy alone. The patients presented with hypertension, significant proteinuria, hypoalbuminemia, and dyslipidemia. Kidney biopsies revealed "mesangioproliferative glomerulonephritis with IgA nephropathy," "focal proliferative glomerulonephritis," and "membranous glomerulonephropathy." The former two had marked active urinary sediment. Patients improved on prednisolone and angiotensin-converting enzyme inhibitors. Contrary to the belief that renal involvement in psoriasis is coincidental, we propose that kidney disease may be a common accompaniment of psoriasis, which may be labeled as "psoriatic nephropathy" or "psoriatic kidney disease." The exact mechanism of this entity is yet to be elucidated.