Atrichia caused by mutations in the vitamin D receptor gene is a phenocopy of generalized atrichia caused by mutations in the hairless gene. J Invest Dermatol 117:612-7 Mu ¨ller-Ro ¨ver S, Handjiski B, van der Veen C, Eichmu ¨ller S, Foitzik K, McKay IA et al. (2001) A comprehensive guide for the accurate classification of murine hair follicles in distinct hair cycle stages.

Our study shows that FLG null alleles are associated with increased susceptibility to CICD; whether or not the FLG null allele is an independent risk factor needs further study.

Little is known about cytokines involved in chronic irritant contact dermatitis. Individual cytokine profiles might explain at least part of the differences in the individual response to irritation. Our objective was to investigate the relation between baseline stratum corneum (SC) cytokine levels and the skin response to a single and a repeated irritation test. This study also aimed to determine changes in SC cytokine levels after repeated irritation. Transepidermal water loss (TEWL) and erythema were measured in 20 volunteers after single 24-hr exposure to 1% sodium lauryl sulfate (SLS), and during and after repeated exposure to 0.1% SLS over a 3-week period. SC cytokine levels were measured from an unexposed skin site and from the repeatedly exposed site. Interleukin (IL)-1alpha decreased by 30% after repeated exposure, while IL-1RA increased 10-fold and IL-8 increased fourfold. Baseline IL-1RA and IL-8 values were predictors of TEWL and erythema after single exposure (r = 0.55-0.61). 6 subjects showed barrier recovery during repeated exposure. Baseline IL-1RA and IL-8 levels are likely to be indicators of higher skin irritability after single exposure to SLS. Barrier repair in some of the subjects might explain the lack of agreement between the TEWL response after single and repeated irritation.