(254) Epidemiology of Palmoplantar Pustulosis in Urban China and a Systematic Review

Publication Number: 585

Background: Palmoplantar pustulosis (PPP) is a chronic and refractory pustular dermatosis that mainly occurs on the palms or soles and is largely understudied.

Objectives: The study sought to estimate the nationwide epidemiologyof PPP in China and conduct a systematic review of the published data worldwide.

Methods: A population-based study was conducted using Urban Basic Medical Insurance in China from 2012 to 2016. International Classification of Diseases code (ICD-10: L40.3, L40.2) and Chinese medical termswere used to identify cases and estimate the prevalence and incidence of PPP in China. To summarize the incidence and prevalence of PPP worldwide, a systematic review was done among Web of Science, PubMed, SinoMed (China BioMedical Literature Service System), CNKI (China National Knowledge Infrastructure), and Wanfang Database up to January 2022, using the terms “palmoplantar pustulosis”, “incidence” and “prevalence”. Two researchers independently reviewed the title, abstract and full-text and extracted data from the studies relevant to the objectives.

Results: The crude prevalence and incidence of PPP in 2016 in China were 2.73 (95% CI 2.22 to 3.24) and 1.56 (95% CI 1.15 to 1.96) per 100,000 person-years, respectively. We found a higher prevalence (2.91 vs. 2.49) and incidence (1.75 vs. 1.42) in females than in males, which showed a bimodal age distribution, with the first peak at 0-3 age group and the second peak at 30-39. Five relevant studies were included in the systematic review. The prevalence of PPP ranged from 5 to 120 per 100,000 person-years, i.e., Denmark 5, United States 9, Sweden 26, Korean 51, Germany 80/91, and Japan 120 per 100,000 person-years. Only one study calculated incidence which was 12.70 per 100,000 person-years in Sweden, and it was 5.40 per 100 000 person-years when the strict case criteria was used. Three studies reported the mean age of PPP from 52.20 to 61.20, and one study from Sweden said onset age was 56.40.

Conclusions: The previous proposal that the prevalence and incidence of PPP might be higher in Asia than in Western countries was not supported. For the first time, our study found a bimodal pattern with the first peak onset at the 0-3 age group, which was corresponding to the innate immune dysfunction in the etiology of PPP. PPP mainly affected labor force population, suggesting a heavy indirect disease burden. And considering the high unmet need for treatment, it was appealing for more attention in this annoying disease.