A study of skin barrier function in atopic eczema using the patch test and transepidermal water loss

Yoo, Hyoung Cheol; Lee, Jee Bum; Lee, Seung Chul; Won, Young Ho

Abstract

BACKGROUND AND OBJECTIVE
: ?The etiology of atopic dermatitis is still not clear. Atopic dermatitis is known to develop through immunological and non-immunological pathomechanisms. The delayed hyper- sensitivity reaction in atopic dermatitis has been reported as decreasing due to disturbance of cellular immunity. However, in recent days, there is a dispute as to whether disturbed epidermal barrier of atopic dermatitis could elicit a delayed type hypersensitivity reaction by an acceleration in the penetration of allergen. The aim of this study was to determine whether transepidermal water loss (TEWL) increased in atopic dermatitis, and whether the TEWL differed with a presence of delayed type-skin reaction. In addition, the prevalence of positive patch test reaction and TEWL were measured in atopic dermatitis and normal controls.
METHODS
We performed the patch test with 24 Korean standard allergens and 5 aeroallergens on 38 atopic dermatitis patients. TEWL was measured using DermaLab (Cortex technology, Denmark) on 38 patients with atopic dermatitis and 40 normal controls.
RESULTS
17 (44.7%) patients with atopic dermatitis had positive reactions on the patch test. The frequency of positive allergens was in the following order: nickel sulfate (18.4%), thimerosal (15.8%), D. pteronyssinus (15.8%), and potassium dichromate (13.1%). TEWL values of both clinically normal skin and eczematous skin in atopic dermatitis patients were higher than those of normal controls. There was no statistically significant difference in TEWL values of normal skin of atopic dermatitis between the positive patch test and negative patch test groups. In positive reaction sites of aeroallergen patch test, the TEWL increased in comparison with both the control site and the positive classical patch test reaction site but it was not statistically significant.
CONCLUSION
These results revealed that epidermal barrier is disturbed in atopic patients and suggested that various allergens might easily penetrate the skin to induce the delayed-type hypersensitivity reaction.