Air pollution and exacerbation of skin itching and sleep disturbance in Iranian atopic dermatitis patients

Background For about three decades now, the number of people suffering from atopy including atopic dermatitis (AD) has been increasing in developed countries. Genetic background and environmental factors including air pollution play an effective role in its incidence. This study examined the association between air pollutants and exacerbation of AD symptoms including sleep disturbance and itching in AD patients of Tehran. Methods In this panel study, 31 patients with AD who admitted to Razi Hospital, dermatology hospital in Tehran, entered the research. Daily information including questions on disease symptoms (sleep disturbance, itching) and duration of outdoor stay (in hours) were collected using a questionnaire. The mean 24-h concentrations of PM 2.5 and PM 10 pollutants were obtained from the Air Quality Control Company. The relationship between the concentrations of the pollutants and exacerbation of the disease symptoms was investigated using the GEE (Generalized Estimating Equations) model. Results There was a significant relationship between the concentrations of air pollutants and exacerbation of sleep disturbance and itching on the same day, before, and after adjusting the effects of the confounding variables, so that the estimated odds ratios (95% confidence interval) between PM 10 and PM 2.5 and exacerbation of itching were 1.06 (1.02–1.10) and 1.17 (1.07–1.28), respectively. Conclusions There was a significant statistical relationship between the concentration of particulate matter (PM 2.5 and PM 10 ) and exacerbation of sleep disturbance and itching. PM 2.5 showed a stronger relationship with the exacerbation of symptoms compared to PM 10 .