The epidemiology of pediatric psoriasis: A nationwide cohort study in Taiwan

Psoriasis can affect individuals of all age groups. While the epidemiology of psoriasis in adults has been extensively studied, there is limited research specifically investigating pediatric cases. This study aimed to investigate the prevalence and incidence of skin psoriasis (PsO) and psoriatic arthritis (PsA) among pediatric patients in Taiwan. A nationwide cohort of 17 535 patients with psoriatic diseases under the age of 18 was enrolled from the National Health Insurance Research Database for the period 2000–2013, including 16 129 PsO patients and 2022 PsA patients. The age- and sex-standardized prevalence and incidence of pediatric PsO and PsA were calculated. The 2007 yearly reports of age- and sex-specific distribution of the general population was adopted as a standard. The results showed that between 2000 and 2013, the prevalence for pediatric PsO increased from 0.03% to 0.07%, and from 0.003% to 0.014% for pediatric PsA. During the same period, the incidence slightly decreased from 19.81 to 17.55 per 100 000 for pediatric PsO but increased from 1.02 to 5.06 per 100 000 for pediatric PsA. Adolescents (12 to <18 years) had higher prevalence and incidence rates of PsO and PsA than children (aged ≤ 12 years), with no sex difference observed in either age group. PsA preceding PsO was more common among children than adolescents (27.07% vs. 13.46%). This study provides important insights into the prevalence and incidence of psoriatic diseases in the pediatric population. Further research is needed to identify risk factors for pediatric psoriasis and to investigate its long-term health outcomes.