Patch testing in Atopic and Non-Atopic Dermatitis

Kang, Hyun Ah; Park, Hyun Jeong; Kim, Hyung Ok; Kim, Chung Won

Abstract

BACKGROUND: The frequency and importance of contact allergy in patients with atopic dermatitis(AD) have been debated. Although the study about patch test in AD is common in foreign countrles, it is rare in our country.
OBJECTIVE
We performed this study to examine the patch test in patients with AD and to know the frequency of contact sensitization and the correlation between metal allergy history and patch test reaction to nickel in patients with AD and non-atopic dermatitis(NAD)
METHODS
One hundred nine patients with AD and one hundred twelve patients without AD were patch tested and questioned about history of metal allergy.
RESULTS
1. The contact sensitivity rate in AD was higher than NAD by 85.3%, 72.3% respectively. But there was statistically no significant difference in the two groups. 2. Positive contact allergens in all patients were cobalt, chromate, nickel, thimerosal, mercury. 3. Positive contact allergens in AD were cobalt, nickel, potassium, thimerosal, formaldehyde, neomycin and in NAD were cobalt, chromate, nickel, mercury, fragrance mix, 4-phenylenediqamine base. 4. The frequency of metal allergy history in all patients was 29% and it was 37.6% in AD and 20.5% in NAD. 5. Patients with metal allergy history had higher positive rate to nickel than patients without metal allergy history. 6. Patients with metal allergy history and AD had higher positive rate to nickel than patients with metal allergy history and NAD. 7. Patients who were positive to nickel were also positive to cobalt, chromate.
CONCLUSION
This study shows that contact sensitivity is relatively common in AD, and metals including nickel are important allergens in AD. Therefore when the symptoms of AD are aggravated, it is important to perform the patch test, considering the possibility of contact dermatitis.