Transepidermal Water Loss As A Biological Marker In Atopic Dermatitis In Children

Abstract

RATIONALE: Studies which have compared transepidermal water loss (TEWL) between atopic and non-atopic skin have yielded conflicting results; furthermore, most of these studies were done in Asian and Caucasian populations; there is insufficient data in African-Americans.METHODS: Caucasian and African-American subjects with atopic dermatitis (AD) were sequentially recruited from Allergy and Dermatology clinics at Cincinnati Children's Hospital Medical Center. TEWL was measured to assess barrier function on non-lesional normal appearing skin at 4 different sites (volar forearm, dorsal arm, lower leg and cheek) in 4 groups of children: (1) AD, atopic; (2) AD, non-atopic; (3) controls with asthma or allergic rhinitis, but no AD; (4) non-atopic, healthy controls. Skin prick testing and/or RAST for common aeroallergens were done on all study subjects, and AD severity was assessed by objective SCORAD.RESULTS: Caucasian cases had consistently higher TEWL measurements than African-Americans, and this difference was significant (p < 0.05) at volar forearm and lower leg. TEWL values were significantly higher (p < 0.05) in AD patients (Groups 1 and 2) compared to both control groups at most of the anatomical sites in both races. There was no significant difference in TEWL between Groups 1 and 2 for both races at any of the body sites.CONCLUSIONS: TEWL in normal appearing skin was significantly increased in children with AD compared to atopic and non-atopic control groups. Caucasian children with AD had consistently higher TEWL measurements than African-Americans. TEWL may be a useful biomarker for AD and should be evaluated in prospective studies. RATIONALE: Studies which have compared transepidermal water loss (TEWL) between atopic and non-atopic skin have yielded conflicting results; furthermore, most of these studies were done in Asian and Caucasian populations; there is insufficient data in African-Americans. METHODS: Caucasian and African-American subjects with atopic dermatitis (AD) were sequentially recruited from Allergy and Dermatology clinics at Cincinnati Children's Hospital Medical Center. TEWL was measured to assess barrier function on non-lesional normal appearing skin at 4 different sites (volar forearm, dorsal arm, lower leg and cheek) in 4 groups of children: (1) AD, atopic; (2) AD, non-atopic; (3) controls with asthma or allergic rhinitis, but no AD; (4) non-atopic, healthy controls. Skin prick testing and/or RAST for common aeroallergens were done on all study subjects, and AD severity was assessed by objective SCORAD. RESULTS: Caucasian cases had consistently higher TEWL measurements than African-Americans, and this difference was significant (p < 0.05) at volar forearm and lower leg. TEWL values were significantly higher (p < 0.05) in AD patients (Groups 1 and 2) compared to both control groups at most of the anatomical sites in both races. There was no significant difference in TEWL between Groups 1 and 2 for both races at any of the body sites. CONCLUSIONS: TEWL in normal appearing skin was significantly increased in children with AD compared to atopic and non-atopic control groups. Caucasian children with AD had consistently higher TEWL measurements than African-Americans. TEWL may be a useful biomarker for AD and should be evaluated in prospective studies.