Skin irritations caused by chemicals found in toilet-seat cleaners appear to be making a comeback in pediatricians’ offices, according to a prominent Baltimore researcher.

“Toilet-seat dermatitis is one of those legendary conditions described in medical textbooks and seen in underdeveloped countries, but one that younger pediatricians have not come across in their daily practice,” says Bernard A. Cohen, MD, director of pediatric dermatology at Johns Hopkins Children’s Center.

“If our small analysis is any indication of what’s happening, we need to make sure the condition is on every pediatrician’s radar,” he says.

The causative culprits are harsh chemicals like phenol and formaldehyde, as well as exotic wooden toilet seats. Phenol has been associated with dermatitis and both second- and third-degree burns, while formaldehyde is a known health hazard and carcinogen.

Wooden seats—especially those covered with varnishes and paints—are a returning trend in bathroom décor, note Dr. Cohen and his colleagues in the February issue of Pediatrics.

Children can develop irritation after repeated use of a wooden seat or ongoing exposure to chemical residues. Dr. Cohen urges pediatricians to ask parents about home and school toilet seats and cleaners when treating a toddler or young child with irritated buttocks or upper thighs.

While dermatitis is relatively benign, many pediatricians may treat it incorrectly if they fail to pinpoint the source. This, in turn, can lead to persistent or worsening inflammation, with painful, itchy skin eruptions. Chronic skin irritation is also vulnerable to bacteria and may lead to more serious infections that require oral antibiotics.

“Some of the children in our study suffered for years before the correct diagnosis was made,” says lead investigator Ivan V. Litvinov, PhD, of McGill University in Montreal.

To prevent toilet-seat dermatitis, Dr. Cohen and his colleagues recommend:

1. Use of paper toilet-seat covers in public restrooms, including hospital and school restrooms
2. Replacing wooden toilet seats with plastic ones
3. Cleaning toilet seats and bowls daily
4. Avoiding harsh store-brand cleaners, which often contain skin irritants