Ambient Air Pollution, Meteorological Factors and Outpatient Visits for Eczema in Shanghai, China: A Time-Series Analysis

Abstract

Environmental irritants are important risk factors for skin diseases, but little is known about the influence of environmental factors on eczema incidence. In this time-series study, our objective was to examine the associations of environmental factors with outpatient visits for eczema. Daily outpatient visits between 2007 and 2011 (1826 days) were collected from Huashan Hospital in Shanghai, China. We used an overdispersed generalized additive model to investigate the short-term association between environmental factors and outpatient visits for eczema. Daily outpatient visits for eczema were significantly associated with air pollution and meteorological factors. For example, a 10 µg/m 3 increase of 7-day (lag 06) average concentrations of PM 10 (particulate matter no greater than 10 microns), SO 2 , NO 2 was associated with 0.81% (95% confidence intervals (CI) 0.39%, 1.22%), 2.22% (95% CI: 1.27%, 3.16%) and 2.31% (95% CI: 1.17%, 3.45%) increase in outpatient visits for eczema, respectively. A 10 • C elevation of temperature on lag 0 day were associated with 8.44% (95% CI: 4.66%, 12.22%) increase in eczema visits, whereas 10 unit decrease of 7-day average relative humidity were associated with 10.86% (95% CI: 8.83%, 12.89%) increase in eczema visits. This study provided clear evidence of ambient air pollution, high temperature and low relative humidity on increasing the incidence of eczema in Shanghai, China.

The interactive effects between air pollution and meteorological factors on the hospital outpatient visits for atopic dermatitis in Beijing, China: a time‐series analysis

“…Acute effects of air pollution on AD were also found in previous studies. A similar study in Shanghai, China also found the strongest effects between air pollutants and outpatient visits for eczema at lag0 . A panel study in Korea found an increase in PM 10 and NO 2 by 10 units increased the risk of eczema symptoms on the same day by 3.2% (95% CI: 1.5%, 4.9%) and 5.0% (95% CI: 1.4%, 8.8%), respectively .…”

Associations between air pollution, climate factors and outpatient visits for eczema in West China Hospital, Chengdu, south‐western China: a time series analysis

“…Furthermore, patients would sweat more in warm seasons, and this might directly irritate the skin lesions of eczema combining with air pollutants. 10 However, our study results still apply to a growing number of people suffering from eczema and throw lights on relationships between environmental factors and eczema. 8,10,41,47 The univariate analysis and multivariate analysis of overall effects showed different effects of environmental factors on male and female outpatients with eczema.…”

“…10 On the contrary, the daily eczema outpatients were significantly negatively associated with relative humidity, which indicated relative humidity might play a protective role in eczema. 10 On the contrary, the daily eczema outpatients were significantly negatively associated with relative humidity, which indicated relative humidity might play a protective role in eczema.…”

“…However, it exhibited an intricate pattern in the lagged effect analysis that it was positively correlated with visits for eczema immediately then turned negatively, which might reflect the 'harvesting effect', namely eczema patients supposed to visit the clinics in following days have their skin problems aggravated in advance due to the higher temperature. Male patients were more vulnerable to the change in climate factors like relative humidity and barometric pressure, and male patients were more susceptive to PM 10 . Furthermore, patients would sweat more in warm seasons, and this might directly irritate the skin lesions of eczema combining with air pollutants.…”

“…Some studies have shown that lots of internal and external factors provoked eczematous lesions, including genetic predisposition, stress, infections, food intake, inhalant allergens and other daily objects. 10 However, recent studies have not adequate evidence for the association between eczema and environmental factors while our knowledge regarding the effects of air pollutants on skin health is limited. 7 Several studies suggested that seasonal climate changes might lead to the seasonal variation of prevalence and clinical features in eczema.…”