Background: Recent global data show an increasing prevalence of psoriasis and psoriatic arthritis in western countries. Objective: The current study analyzed the trend of prevalence rates of psoriasis and psoriatic arthritis in Taiwan and examined biologic prescription patterns by different specialties. Methods: Data were accessed from the national payer National Health Insurance Research Database in Taiwan. This study protocol was approved by Joint Institutional Review Board established by Medical Research Ethics Foundation (No 13-S-001). Results: Between 2003 and 2013, the prevalence of psoriasis and psoriatic arthritis increased by 41% (from 15.54 to 21.90 per 10,000 population) and 191% (from 0.45 to 1.31 per 10,000 population), respectively, while the prevalence of psoriatic arthritis among patients with psoriatic disease increased from 6.3% to 12.7%. Dermatologists are the main caregivers for patients with psoriasis and psoriatic arthritis; however, data suggest a decreasing trend in the proportion of dermatologists for psoriasis patients from 24.7% between 2003 and 2008 to 10.74% between 2008 and 2013, with a corresponding decrease in dermatologists for psoriatic arthritis patients from 62.30% to 44.65% during the same periods, respectively. In 2013, of the 51,191 patients with psoriasis, only 596 (1.16%) received biologics (73.3% by dermatologists and 25.8% by rheumatologists), while 1120 of the 7470 (14.99%) psoriatic arthritis patients received biologics (72.8% by rheumatologists and 223% by dermatologists). The proportion Of biologics use was 1.12% and 7.75% among all patients with only psoriasis and 8.01% and 26.70% among all patients with psoriatic arthritis seen by dermatologists and rheumatologists, respectively. Conclusion: The prevalence of psoriasis and psoriatic arthritis is increasing in Taiwan. The use of biologics in patients with psoriatic arthritis was comparable to that reported in previous studies in the United States and Europe; however, the use of biologics remained low in patients with psoriasis in Taiwan. (C) 2016 Japanese Scciety for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.