Table 1.

Summary characteristic of studies. AD: atopic dermatitis; PM: particulate matter.

Reference	Year of Study	Location	Pollutant	Diagnosis	Total No.	Age
Vierko et al., 2010 [20]	2008–2009	Europe	PM10	Pigment spots, wrinkles, skin aging	400	>18
Song et al., 2011 [23]	2009	South Korea	PM10, PM2.5	Skin itching	670	8–12
Peng et al., 2016 [24]	2015	China	PM2.5	Skin itching	611	10–15
MSa et al., 2013 [25]	2011	France	PM10	Current eczema	518	10–12
Wang et al., 2015 [21]	2010	China	PM10	AD	5925	8–15
Morgenstern et al., 2008 [26]	2005	Germany	PM2.5	Eczema	10,750	4–6
Kim et al., 2013 [27]	2009–2010	South Korea	PM10	AD	1880	8–12
Tang et al., 2017 [22]	2011	Taiwan	PM10, PM2.5	AD	5115	20–30
Shah et al., 2016 [28]	2015	United States	PM10	Eczema	128	28–30
Brauer et al., 2007 [16]	2004–2006	Germany	PM2.5	Eczema, itchy rash	6982	3–6
Lee et al., 2011 [29]	2010	South Korea	PM10	AD	51	2–3
Gehring et al., 2009 [30]	1996–2000	Netherlands	PM2.5	Allergen	3863	8
Kim et al., 2017 [31]	2013–2014	South Korea	PM10	AD	35,158	4–8