AN EPIDEMIOLOGIC-STUDY OF THE INFLUENCE OF SEASON (COLD AND DRY AIR) ON THE OCCURRENCE OF IRRITANT SKIN CHANGES OF THE HANDS

In the course of an ongoing cohort study on constitutional and occupat ional risk factors for the development of irritant hand dermatitis in hairdressing apprentices, an increased prevalence of irritant skin cha nges was noted in a subgroup examined during particularly cold winter months, Prompted by this observation, the importance of several meteor ological factors (day means of temperature, relative and absolute humi dity) was assessed in extensive statistical analyses based on data of 742 participants, supplemented by meteorological information obtained from the German Meteorological Service (DWD). There were significant a ssociations of existing hand dermatitis with low temperature and low a bsolute humidity (Mann-Whitney U-test, P < 0.0001), but not with relat ive humidity (P = 0.38). Logistic regression analysis, including known determinants of irritant hand dermatitis in this setting, showed that low temperature and low relative humidity tended to be risk factors ( OR = 1.66 and 1.57, respectively, for the lower quartiles, P = 0.07 in both cases), and confirmed that absolute humidity significantly influ enced the occurrence of irritant hand dermatitis (OR = 2.06 for < 4.8 mg/L, P < 0.01). Thus, these environmental factors must be regarded as possible confounders in the analysis of future epidemiological studie s on irritant hand dermatitis and should be considered in multifactori al analyses.