Mercury-associated minimal change disease induced by whitening cream: a case report.

Mercury-associated minimal change disease (M-MCD) is a rare form of secondary minimal change disease (MCD) caused by chronic mercury exposure. Given its rarity and nonspecific clinical presentation, M-MCD is frequently underrecognized in clinical practice. We report the case of a 32-year-old woman who presented with nephrotic syndrome following 4 months of applying a skin-whitening cream. Markedly elevated urinary mercury concentrations were detected, and renal biopsy confirmed MCD with immunoglobulin M (IgM) deposition. The patient received four courses of sodium dimercaptopropane sulfonate chelation therapy combined with glucocorticoids. Complete remission of proteinuria was achieved within 1 month, accompanied by normalization of urinary mercury levels. This case underscores the necessity of obtaining a detailed exposure history in patients with unexplained nephrotic syndrome, particularly among young women using skin-whitening cosmetics. Prompt recognition of mercury exposure and timely chelation therapy are essential for achieving remission; adjunctive glucocorticoids may be considered in selected patients with severe disease or suspected immune- mediated injury.