Print Version

For Release: September 21, 2010
David Corriveau, Media-Relations Officer, Dartmouth-Hitchcock Medical Center, Dartmouth Medical School, at or 603-653-1978

Zug presents research to European dermatologists

Kathryn A. Zug, M.D.

Lebanon, N.H.—Dartmouth dermatologist Kathryn A. Zug, M.D., recently traveled to France to share with some 800 European colleagues the findings from a decade of research on cases of eczema-like symptoms among patients.

Speaking at the invitation of the European Society of Contact Dermatitis (ESCD) at the Palais des Congrès in Strasbourg on September 17, Zug presented the findings from 10 years of data gathered by the North American Contact Dermatitis Group (NACDG), of which she is one of 13 members and secretary-treasurer.

"In patients over 65, the incidence of allergy to certain preservatives was markedly increased," says Zug, a professor of medicine at Dartmouth Medical School (DMS). "This is speculated to be a result of increase exposure to products over time."

At her clinic for contact and occupational allergies at Dartmouth-Hitchcock Medical Center (DHMC), Zug evaluates about 150 patients a year, many of them referrals from northern New England, New York state and Massachusetts. They undergo tests in which small amounts of different substances - such as metals, ingredients of personal-care products, including preservatives, hair dye, and fragrance materials - to patches that are applied to skin for sensitization.

Zug also told the European dermatologists that since the 1970s, North American dermatologists have seen the frequency of sensitivity to preservatives double among patients, though it appears to have leveled off over the past decade. Many preservatives are needed to prevent spoilage and contamination in personal care products, medicaments, and in many occupation-related substances.

"For some specific preservatives, the frequency of a positive test result is about double that of European countries," Zug says. "The reasons for this are not clear. While in most instances the allowable concentrations for specific preservatives is either the same or similar, it is possible there are some differences in preservative use concentration or use of products that could also explain the differences in allergic frequency. This requires some further study. The European Union countries have a history of more protective legislation regulating exposure allowances as well."

Sometimes, Zug adds, a contact allergy develops to a substance in a product that the patient has used or worked with for years.

"The term hypoallergenic does not have a meaning defined by the Food and Drug Administration," she concludes. "Just because a product is labeled as being hypoallergenic doesn't mean it will not cause allergy."

Zug is a past president of the American Contact Dermatitis Society. She is director for DMS' dermatology course for second-year medical students and co-author of the book, Skin Disease: Diagnosis and Treatment - the No. 2 best-selling dermatology book on The book is in its third printing, and available in Polish, Spanish, Portuguese, Greek, Russian as well as English, with a Chinese edition now in preparation.


Return to News Releases