Don't Forget the Topical Nonsteroidal Anti-inflammatory Drugs (NSAIDs)

Introduction: Non-steroidal anti-inflammatory drugs (NSAIDs) are known to cause multiple adverse effects to the kidneys including acute kidney injury, interstitial nephritis, hyperkalemia, membranous glomerulonephritis, minimal change disease (MCD) or papillary necrosis. Topical NSAID use is usually considered safe and low risk for these adverse effects; however, it still needs to be considered. Case Description: A 53-year-old male with poorly controlled diabetes mellitus (DM) type 2 (HgA1C 9.8%) presents with acute onset of bilateral lower extremity, abdominal distention and shortness of beath. Patient was found to have urine albumin/creatinine ratio (UACR) or 6215 mg and nephrotic syndrome. Urine did not show any active sediment and he had no know personal or family history of kidney disease. Patient had been using regularly topical diclofenac for back and knew pain. Differential diagnosis included DM nephropathy, focal segmental glomerulosclerosis (FSGS) due to obesity, primary FSGS and MCD. All proteinuria serology including hepatitis B and C, HIV, syphilis, immunofixation, phospholipase A2R, ANCA, complement, kappa/lambda, QuantiFERON gold were all within normal limits and patient did not have any evidence of diabetic retinopathy. Given acute onset of nephrotic syndrome and no evidence of retinopathy, patient underwent kidney biopsy which revealed minimal change disease. Patient did not have any history of atopy, or lymphoproliferative disorder. He was instructed to discontinue topical NSAIDs and follow up UACR in 1 month normalized to 7.2 mg. Discussion: Diabetic kdiney diease is the most common cause of proteinuria and can often cause nephrotic syndrome, however it usually presents insidiously and coincides with diabetic retinopathy. In patients who do not have the typical natural history, kidney biopsy evaluation is imperative to not miss other etiologies. Additionally, although nephrologist often screen for oral NSAIDs during history evaluation, often topical NSAIDs are considered safe. However, if used in excessive amounts this may lead to systemic complications such as MCD in this case.