Oxalate nephropathy associated with glyoxylate-containing hair-straightening products: a call for caution.

Recent reports have described acute kidney injury in otherwise healthy individuals after exposure to hair-straightening products. In this issue, Robert et al. help elucidate the underlying mechanisms in a murine model that replicates the human pathology. Cutaneous absorption of glyoxylic acid from hair-straightening products and its subsequent conversion to oxalate are identified as crucial steps in the development of oxalate nephropathy. This newly described "skin-kidney" axis expands our understanding of oxalate metabolism, calls for additional studies to explore susceptibility to acute kidney injury following cutaneous glyoxylate exposure, and warrants vigilance around the use of these products.