Einfluss von flüchtigen organischen verbindungen und hausstaubmilben-allergen auf die hautfunktion beim atopischen ekzem

Background: Epidemiologic studies indicate environmental pollutants to be involved in the increase in prevalence of allergic diseases. In human exposure studies volatile organic compounds (VOC) have been shown to cause exacerbations of allergic asthma, whereas no data concerning atopic eczema are available. Methods: The effect of airborne VOC on skin of patients with atopic eczema and controls in the presence or absence of house dust mite allergens was investigated. In a double-blind crossover study twelve adults with atopic eczema and twelve matched healthy volunteers were exposed on their forearms to Dermatophagoides pteronyssinus and subsequently to a mixture of 22 VOC (M22, 5 mg/m ³) in a total-body exposure chamber for 4 h. Transepidermal water loss and skin blood flow were measured in all subjects before, during and after exposure. Additionally, an atopy patch test with D. pteronyssinus was applied to the skin after exposure. Results: A significant increase in transepidermal water loss was observed 48 h after exposure to VOC as compared to exposure with filtered air in all individuals (mean difference: +34%; 95% confidence interval: 7-69%). Prior exposure to D. pteronyssinus resulted in a significant rise of dermal blood flow after 48 h in patients with atopic eczema, but not in controls. Six of seven patients showed enhanced atopy patch test reactions to house dust mite allergen after previous exposure to VOC. Conclusion: The results show that exposure to VOC - at concentrations commonly found in indoor environments - can damage the epidermal barrier and enhance the adverse effect of D. pteronyssinus on sensitized subjects with atopic eczema. These findings may contribute to a better understanding of the mechanisms underlying the increase in prevalence and exacerbation of atopic eczema.