Peds knowledge advances

Sep 01, 2004, 4:00am

Better care of infants contributes to decline in diaper rash, cradle cap; psoriasis on the rise

Sometimes developments in pediatric dermatology stem more from changes in understanding of children's skin conditions than actual changes in what children are experiencing.

That was the message Bernice R. Krafchik, M.D., University of Toronto, professor emeritus, had for dermatologists at the annual Canadian Dermatology Association meeting recently. In practice for more than 30 years, Dr. Krafchik has seen the understanding of pediatric conditions grow, and has seen some conditions, such as diaper dermatitis, become a thing of the past because of lifestyle changes.

"We used to see diaper dermatitis quite commonly," says Dr. Krafchik, "but it is something we don't see very much now because disposable diapers have actually reduced the incidence of diaper dermatitis enormously, as well as inhibiting candida infections. I think they're great."

"We do see cradle cap, but cradle cap does not mean anything," she says. "Cradle cap is just the retention of keratin on the vertex of the scalp. It could be indicative of atopic dermatitis, or it could occur in a normal child, or it could be a seborrheic condition. So to make the diagnosis of seborrheic dermatitis only on cradle cap doesn't mean anything."

Dr. Krafchik said that redness in other areas including the genital area is needed to justify that diagnosis.

Care influences conditions Dr. Krafchik explains a change in the way parents care for infants is one reason seborrheic dermatitis has decreased in incidence.

"Most parents wash their baby's scalps every day. If seborrheic dermatitis is infection-based, then they are washing away the oil which would be needed to get that kind of inflammation."

On the other hand, Dr. Krafchik says that psoriasis is being diagnosed more often now than in the past.

"I don't know that it is occurring more often," she says. "I think it's more a matter of it being recognized more now."

Dr. Krafchik says that a lot of pediatric skin conditions are linked to atopic dermatitis, she believes improperly.

"I think we are basically dealing with a number of different diseases -a group of atopiform diseases. We don't always know how to distinguish one from another because we don't routinely do IgEs on all of these patients.

"Infants should have evidence of atopy before calling it atopic dermatitis. At the moment, we are just treating the inflammation, whatever the etiology. But I think there is a small subset that is actually atopic dermatitis as opposed to any dermatitis that occurs in infancy."

Identification needed She does think it's important to find ways to differentiate the types of dermatitis.

"We need to identify the gene that determines atopic dermatitis, and that will help with the ultimate prognosis," she says.

Dr. Krafchik also sees a problem with the labels of erythema multiforme (EM), toxic epidermal necrolysis, (TEN) and Stevens-Johnson syndrome (SJS), and discussed these topics.

"I don't think SJS really exists because I don't think people really know what it is, and don't have their definitions clear - that leads to difficulty in determining treatments because there are overlapping diagnoses."

Dr. Krafchik says the understanding of congenital nevi has changed substantially.

"In the 1970s, people used to think the incidence of melanoma resulting from congenital nevi was 20 percent - with about 60 percent of those cases occurring before the age of 10. Now, we feel the incidence of congenital nevi-related melanoma is really less than 1 percent."

Doctors used to remove the nevi as a matter of course, and according to Dr. Krafchik, that might not be the best treatment for lesions that involve much of the trunk.

Patients with large congenital nevi may develop leptomenigeal melanosis and those may develop melanoma. Dr. Krafchik says the percentage who develop melanoma is unknown, but occurrences are believed to be rare.