Incidence and Clinical Characteristics of Active Tuberculosis in Psoriasis Patients From a High‐Burden Setting: An 18‐Year Retrospective Study of 86 Patients

Real-world data on concurrent psoriasis and active tuberculosis (TB) remain limited, particularly in high TB-burden settings. This retrospective study evaluated the incidence, prevalence, and clinical characteristics of psoriasis patients with active TB who had received topical or systemic treatments. Medical records from 13 066 psoriasis patients who presented at Siriraj Hospital over 18 years were reviewed. Among these, 86 (0.66%) developed active TB, yielding an incidence range of 135-1332 per 100 000 psoriasis patients. The mean patient age was 50.4 ± 15.7 years; 63 were men and 23 were women. Pulmonary TB occurred in 55 patients (64.0%), whereas 31 (36.0%) developed extrapulmonary TB. Male sex and smoking were associated with pulmonary TB. The most common pulmonary symptoms were chronic cough (65.5%) and dyspnoea (60.0%), although 7.3% were asymptomatic. Time to TB onset was shorter for extrapulmonary cases (5.7 ± 5.1 years) than for pulmonary cases (7.4 ± 6.5 years), but this difference was not statistically significant. Extrapulmonary disease most frequently involved the lymph node and pleura (25.8%) or the gastrointestinal tract (16.1%). Notably, all four patients who received infliximab within 1 year before TB diagnosis developed extrapulmonary TB. In conclusion, the incidence of TB in psoriasis patients in endemic regions may be high. Geographic factors, sex, smoking, and treatment history appear to influence TB risk. Close monitoring is critical, particularly in high-burden settings.