Variability in transepidermal water loss of the skin: evaluation of a method to assess susceptibility to contact dermatitis in epidemiological studies.

Transepidermal water loss (TEWL) has been suggested to be a measure which can be used to identify subjects at risk for the development of contact dermatitis. Transepidermal water loss is high when the barrier function of the skin is impaired. It is assumed that subjects with a high TEWL have skin which is more permeable to substances causing contact dermatitis. The inter-individual and intra-individual variability of simultaneous TEWL measurements and TEWL measurements over a period of three weeks were estimated in healthy individuals. The intra-individual coefficient of variation (CV) of simultaneous measurements was 13.5%. The intra-individual coefficient of variation of the measurements on consecutive days was somewhat higher (15.1%). The intra-individual coefficients of variation were low compared to the inter-individual coefficients of variation. The results indicate that transepidermal water loss is a stable personal characteristic, which can be studied as a risk factor in epidemiologic studies on contact dermatitis.