Which Areas Are Still Left in Biologics Responsive Korean Patients with Moderate to Severe Plaque Psoriasis

BACKGROUND: Psoriasis localized to certain body areas, such as the scalp, nails, palms, soles, intertriginous regions, and genital regions, is reportedly difficult to treat. OBJECTIVE: To investigate the biologics-resistant areas in South Korean patients with psoriasis treated with biologics. METHODS: The study included 50 patients with chronic moderate to severe plaque psoriasis from the Pusan National University Hospital and Chosun University Hospital between October 2019 and September 2020. The patients had at least one psoriatic lesion, were treated with biologics for more than six months, and exhibited a partial or good response (reaching a Psoriasis Area and Severity Index [PASI] score of 1~5 after biologics treatment). RESULTS: A total of 50 patients with psoriasis (32 male, mean±standard deviation 47.8±11 years), with a median PASI score of 1.8, were included. The most common biologics-resistant areas were the anterior lower leg (56.0%), followed by the knee (48.0%) and posterior lower leg (42.0%). The proportion of biologics-resistant areas were obtained for body regions traditionally considered as difficult-to-treat entities, including the fingernails (10.0%), toenails (14.0%), scalp (38.0%), palm (12.0%), sole (14.0%), and genital areas (10.0%). CONCLUSION: This study determined the biologics-resistant areas in South Korean patients, successfully treated with biologics, in a real-world clinical setting.