Defining the Relationship between Daily Exposure to Particulate Matter and Hospital Visits by Psoriasis Patients

Abstract

Background: Although particulate matter likely provokes inflammatory reactions in those with chronic skin disorders like atopic dermatitis, no study has examined the relationship between particulate matter and psoriasis exacerbation.

Objective: This study evaluated possible associations between particulate matter and hospital visits for psoriasis patients in 7 major cities in South Korea.

Methods: We investigated the relationship between psoriasis and particulate matter. To do this, we used psoriasis patient data from the Korean National Health Insurance Service database. In addition, PM₁₀ and PM_2.5 concentration data spanning a 3-year time frame were obtained from the Korea Environment Corporation.

Results: A pattern analysis generated by the sample cross-correlation function and time series regression showed a correlation between particulate matter concentration and the number of hospital visits by psoriasis patients. However, the prewhitening method, which minimizes the effects of other variables besides particulate matter, revealed no correlation between the two.

Conclusion: This study suggests that particulate matter has no impact on hospital visit frequency among psoriasis patients in South Korean urban areas.

Keywords: Particulate matter; Psoriasis.

Fig. 1. The horizontal dashed line indicates the boundary of the rejection region (A, B, D, F). Plotted data are standardized in (C) to compare psoriasis and PM₁₀ (n=156 and the overall maximum lag is k=18). The fitted values of E were generated by assuming the correlation is not spurious and the transfer-function model fits. (A) sCCF values from 7 major cities (Seoul, Busan, Daegu, Incheon, Gwangju, Daejeon, and Ulsan), (B) prewhitened sCCF values from 7 major cities, (C) original psoriasis patient and PM₁₀ data from Seoul, (D) sCCF values from Seoul, (E) time series regression model with spurious correlations, (F) prewhitened sCCF values from Seoul. PM: particulate matter, sCCF: sample cross-correlation function.

Fig. 2. The horizontal dashed line indicates the boundary of the rejection region in (A, B, D, F). Plotted data are standardized in (C) to compare psoriasis and PM_2.5 (n=156 and the overall maximum of lag is k=18). The fitted values of E were generated by assuming the correlation is not spurious and the transfer-function model fits. (A) sCCF values from 7 major cities (Seoul, Busan, Daegu, Incheon, Gwangju, Daejeon, and Ulsan), (B) prewhitened sCCF values from 7 major cities, (C) original psoriasis patient and PM_2.5 data from Seoul, (D) sCCF values from Seoul, (E) time series regression model with spurious correlations, (F) prewhitened sCCF values from Seoul. PM: particulate matter, sCCF: sample cross-correlation function.