We recently reported the case of a patient who experienced three consecutive episodes of acute kidney injury, all of them following a “Brazilian” hair-straightening treatment. The cream used for the straightening procedure contained glyoxylic acid. To examine possible underlying mechanisms causing kidney injury, four groups of mice were exposed to topical application of (i) the straightening product, (ii) a cream containing 10% glyoxylic acid, (iii) a cream containing 10% glycolic acid or (iv) a control cream. Application of glycolic acid slightly increased urine oxalate excretion, while glyoxylic acid and the straightening product dramatically increased urine oxalate excretion and caused calcium oxalate nephropathy after transcutaneous absorption. Thus, glyoxylic acid was presumptively absorbed through the skin, metabolized to oxalate and promoted crystallization of calcium oxalate in urine. Hence, cosmetic products containing glyoxylic acid may induce acute kidney injury and should be discontinued. Further studies are needed to investigate the metabolism of glycolic acid and glyoxylic acid following topical application.

中文翻译：

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含有乙醛酸的直发化妆品可诱发结晶性肾病


我们最近报道了一名患者连续经历 3 次急性肾损伤的病例，所有这些患者都是在接受“巴西”直发治疗后发生的。用于拉直程序的乳霜含有乙醛酸。为了检查导致肾损伤的可能潜在机制，四组小鼠暴露于局部应用 （i） 直发产品，（ii） 含有 10% 乙醛酸的乳膏，（iii） 含有 10% 乙醇酸的乳膏或 （iv） 对照乳膏。乙醇酸的应用略微增加了尿草酸盐排泄，而乙醛酸和直发产物显着增加了尿草酸盐排泄，经皮吸收后引起草酸钙肾病。因此，乙醛酸被推定通过皮肤吸收，代谢为草酸盐并促进尿液中草酸钙的结晶。因此，含有乙醛酸的化妆品可能会诱发急性肾损伤，应停药。需要进一步的研究来调查局部应用后乙醇酸和乙醛酸的代谢。