Ionic Components of Particulate Matter 2.5 May Influence Daily Prevalence of Skin Symptom Exacerbations in Allergy Sufferers

(1) Background: To date, little research has epidemiologically examined whether the concentration of particulate matter (PM) 2.5 and its ionic components is related to the prevalence of skin symptom exacerbations. Therefore, this study aimed to clarify this association in patients with allergic diseases. (2) Methods: From 1 February to 31 May 2020, we evaluated the daily prevalence of skin symptoms in outpatients with allergic diseases being treated at Fukuoka National Hospital, Fukuoka, Japan, and measured the concentration of PM2.5 and its ionic components. (3) Results: Univariate analysis showed a statistically significant association between skin symptoms and the concentration of PM2.5 and the ionic components SO42−, NH4+, K+, and Mg2+; multivariate analysis showed a statistically significant association between the daily prevalence of skin symptom and the concentration of the ionic components SO42− or Mg2+. (4) Conclusions: Our findings indicate that the concentration of some PM2.5 ionic components may affect skin symptom in patients with allergic diseases.