Irritant hand dermatitis (IHD) is common in health care workers.
We studied endogenous irritant contact dermatitis threshold by patch testing and exogenous factors such as season and hand washing for their association with IHD in health care workers.
Irritant patch testing with sodium lauryl sulfate (SLS), sodium hydroxide, and benzalkonium chloride at varying concentrations was measured in 113 health care workers. Examination for hand dermatitis occurred at 1-month intervals for a period of 6 months in the Midwestern United States.
Positive patch testing to low-concentration SLS was associated with IHD (P = 0.0310) after adjusting for age, sex, ethnicity, season, history of childhood flexural dermatitis, mean indoor relative humidity, and glove and hand sanitizer usage. Subjects with a positive patch test to SLS were 78% more likely to have occurrence of IHD (incidence rate ratio [IRR] = 1.78; 95% confidence interval [CI], 0.92–3.45). Hand washing frequency (≥10 times a day; IRR = 1.55; 95% CI, 1.01–2.39) and cold season (IRR = 2.76; 95% CI, 1.35–5.65) were associated with IHD. No association was found between history of childhood flexural dermatitis and IHD in this population.
Both genetic and environmental factors are important in the etiology of IHD and should be considered in designing strategies to protect, educate, and treat susceptible individuals.