Corticosteroid creams and ointments are often recommended for soothing a sunburn, but a new study suggests they are unlikely to help.

Topical corticosteroids, like hydrocortisone and betamethasone, are effective for inflammatory skin conditions such as eczema. Sunburns are the manifestation of an inflammatory reaction to damage from UV light, but studies have come to conflicting conclusions as to whether corticosteroid creams, lotions and ointments can help cool the burn.

For the new study, published in the Archives of Dermatology, researchers recruited 20 healthy, sun-sensitive volunteers to test whether topical corticosteroids could offer quick sunburn relief.

All participants had their upper backs exposed to UV-emitting lamps; some areas of their skin were treated beforehand with a moderate- or high-strength corticosteroid cream, while other areas were treated 6 and 23 hours after the UV exposure. One area of skin was left untreated.

The researchers then examined the volunteers’ sunburns one hour after the last corticosteroid application.

They found that in areas of skin treated before UV exposure, the creams did seem to lessen redness. This was not true, however, of skin that was treated after UV exposure - the way corticosteroids would be used in the real world.

The findings suggest that topical corticosteroids “have no effect in reducing sunburn,” lead researcher Dr. Annesofie Faurschou, of Bispebjerg Hospital in Copenhagen, Denmark, told Reuters Health.

The reason, she explained, is that once the sunburn is visible, it is “too late” for corticosteroids to be effective.

Sunburn sufferers can try to find relief by using pain medication, Faurschou said, and “after sun” lotions can cool the skin and offer a temporary reprieve.

“However,” she said, “the severity of the acute sunburn will be the same whether you use topical corticosteroids or not.”

SOURCE: Archives of Dermatology, May 2008.