Diaper rashes are one of the banes of infancy. Most are mild, caused simply by irritation of the skin, and disappear within a few days. But rashes complicated by a fungal infection can persist for weeks, making babies fussy and uncomfortable.
The combination of drugs used to treat these severe rashes is not ideal. One medication has side effects; the other hasn't been tested on children. However, a new topical cream, called Zimycan, appears to safely treat both the cause and the symptoms in infants.
"This cream will be nice to have because these infections are so common and the kids are miserable, which makes the parents miserable too," says Dr. Dennis B. Woo, chairman of the department of pediatrics at Santa Monica-UCLA Medical Center.
Each year, about 400,000 babies suffer from severe diaper rash caused by Candida, a yeast-like fungus that thrives in the warm and moist environment of the diaper. Typically, yeast rashes are a bright, beefy red with sharp, raised borders and white scales on the surface. The main patches are often surrounded by smaller patches and painful pus-filled sores or blisters. In severe cases, the rash can cover the entire diaper area.
Infants get yeast infections when their diapers chafe and break the surface of the skin. When this protective barrier is breached, it's easier for microorganisms such as the yeast fungus to invade the skin, Woo says. Babies taking antibiotics for ear infections or other illnesses are prone to these severe rashes because penicillin kills off bacteria that fight yeast infections.
"And it's not just babies," says Dr. James J. Leyden, a dermatologist at the University of Pennsylvania School of Medicine in Philadelphia who helped develop Zimycan. "Even the very elderly, who are incontinent and unable to care for themselves, are getting these type of diaper rashes."
No drugs have been approved for diaper rash complicated by a yeast infection, but pediatricians often prescribe antifungal agents designed for adults, plus topical steroids to reduce the inflammation. However, prolonged use of steroids can thin a baby's sensitive skin, leaving stretch marks, and may exacerbate bacterial and fungal infections, says Dr. Mary K. Spraker, a pediatric dermatologist at Emory University in Atlanta who assisted in a recent study of Zimycan.
"With the adult antifungal preparations," she adds, "we don't know if they're really safe for babies, or if they provide optimal relief because they have never been tested on infants."
Zimycan, in contrast, contains zinc oxide and a weakened version of miconazole, a fungus-fighting medication used for adults. "Zinc oxide by itself doesn't have much effect on the yeast," Leyden says. "But we found that zinc oxide enhanced the effects of the miconazole, so the two compounds in combination were more potent than when they were used individually."
A recent test comparing Zimycan with a zinc oxide ointment, which is the standard of care for diaper dermatitis, was encouraging. In the study, 236 children younger than 3 who had a Candida yeast infection in the diaper area were treated for seven days with either Zimycan or the zinc ointment. At the end of treatment, the Zimycan group experienced a 72% reduction in signs and symptoms of the disease, versus 25% with the ointment. "These results were exciting because we could prove the cream really works," Spraker says.
(BEGIN TEXT OF INFOBOX)
Keeping babies rash-free
More than half of infants younger than 15 months develop diaper rash at least once every two months because their skin is so sensitive.
Excessive moisture is the primary culprit. When the skin is wet, it rubs against other skin or the diaper, causing friction and redness, especially in the skin folds of the groin and upper thighs. Enzymes and other substances in the stool can also irritate the skin. Babies may also be allergic to the diaper material, soap or laundry detergent.
Today's super-absorbent disposable diapers are better at keeping the skin dry, but experts say diapers should still be changed six or seven times a day, and immediately after stooling. If an allergy is the cause, then changing the diaper, soap or laundry detergent brand usually solves the problem. "If the rash persists more than three days or seems to get worse," says Dr. Mary K. Spraker, "then it's time to see your pediatrician."