Sodium hydroxymethylglycinate (SHMG) is a preservative used in many commercially available products, including shampoos, conditioners, soaps, moisturizers, body sprays, baby wipes, room sprays, cleaning agents, and pesticides. It is in a class of chemicals known as formaldehyde-releasing preservatives. Notably, members of this class have been associated with allergic contact dermatitis, possibly due to the agents themselves, the formaldehyde they release, or both. Studies on SHMG in animals have demonstrated potential for sensitization and dermatitis, and formaldehyde-allergic patients have been reported to improve when products containing SHMG are avoided. Patients and providers need to be aware of this preservative.
From the Department of Medicine, University of California, San Diego, School of Medicine, San Diego, CA, and the Division of Pediatric and Adolescent Dermatology, Rady Children's Hospital, University of California, San Diego, San Diego, CA
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