乌鸦传媒

Rashes from toilet seats are once again afflicting American children, and the rare condition is often misdiagnosed, which may delay proper treatment.

That's the conclusion from a report based of five-cases of toilet-seat contact dermatitis investigated by researchers at Johns Hopkins University School of Medicine and reported in the Jan. 25 issue of Pediatrics.

While toilet-seat dermatitis is commonly thought to result from allergies to wooden seats, the report concludes that another source is plastic toilet seats cleaned with harsh detergents.

"This case series and previous reports have documented that toilet-seat dermatitis is much more common than previously recognized in the U.S. and around the world," Bernard A. Cohen, MD, and colleagues wrote.

"Furthermore, the incidence of this condition is rising in North America because of a resurgent popularity of exotic-wood toilet seats and frequent use of detergents that contain highly irritant/sensitizing compounds such as quaternary ammonium compounds, phenol, formaldehyde, etc. in public restrooms."

Of the cases analyzed by the authors, two occurred in the U.S. and the other three occurred in India.

Both U.S. cases were girls, a 6-year-old who had a rash for over two years before it was correctly diagnosed and a 10-year-old whose rash lasted for a year. In both cases, the rashes seemed to worsen during the school year when the girls were using school restrooms. The younger girl's dermatitis twice became infected with methicillin-resistant Staphylococcus aureus and required treatment with antibiotics.

After doctors determined the rashes were the result of contact with toilet seats and instructed the girls to use toilet-seat covers and apply moisturizers and topical steroids to the affected areas, the eruptions cleared up within a few weeks.

The cases in India included a 14-month old boy and two girls, 12 and 10.

The boy and the 12-year-old girl were both initially misdiagnosed with ringworm and unsuccessfully treated with clotrimazole cream. The other girl was unsuccessfully treated with ayurvedic and homeopathic topical medications before doctors diagnosed toilet-seat dermatitis. Two of the children were instructed to use soaps that only exacerbated the problem.

In all three cases, the rashes cleared up with some combination of topical steroids, using toilet-seat covers, replacing the household toilet seat, and limiting time on the toilet.

The authors distinguished between two types of toilet-seat dermatitis: allergic contact dermatitis, the better described form of the condition, in which a patient develops allergy to wooden toilet seats, and irritant contact dermatitis, in which the rashes result from contact with harsh detergents used on plastic toilet seats.

They noted that detergents used in public restrooms and in hospitals are potentially more irritating to the skin than those used at home and that alkaline detergents are more likely to cause skin irritation than acidic detergents, because they perturb the body's natural acidic environment.

Toilet-seat dermatitis was first identified as an external skin rash in 1927. Exposure to wooden toilet seats and associated varnish, lacquers, and paints led to sensitization and development of an allergic contact dermatitis.

The condition nearly disappeared in the U.S. in 1980s and 1990s, after public facilities and homeowners in the U.S. changed from wooden to plastic toilet seats and sanitary seat covers became readily available.

However, in recent years the number of cases has grown as a result of homeowners installing toilet seats made of exotic woods and the increased use of harsh toilet seat detergents.

Most reports have focused on adults with rashes, but little previous attention has focused on the condition in children. "In this case series we describe toilet-seat contact dermatitis in children and underscore a typical history and physical findings that we hope will aid clinicians in recognizing this disease," the authors wrote.

"It is important to underscore that regular use of toilet-seat covers is the key to success in treatment," the authors wrote. "Such seat covers can be purchased at any major retailer such as Walmart or online.

As an alternative, newspaper cutouts could be used to provide barrier protection. Although it is possible to develop an allergy to toilet-seat covers, none have been reported thus far in the literature."