Introduction The incidence of tuberculosis (TB) or the prevalence of latent tuberculosis infection (LTBI) in psoriasis patients has not been described in the Spanish population. We carried out a study with the objectives: (i) To describe the incidence of TB in patients with psoriasis on systemic treatment in the Spanish population; (ii) To determine the prevalence of LTBI in patients who are candidates for biological treatment; and (iii) To investigate the level of compliance with current recommendations for LTBI and TB screening.
Methods Data were obtained from BIOBADADERM (Spanish registry for systemic biological and non-biological treatments in psoriasis). An analysis was performed of the exposed cohort to determine the prevalence of LTBI and to describe compliance with the screening guidelines.
Results A total of 1425 patients were registered in BIOBADADERM. They included 793 (56%) patients exposed to biological treatment and 632 (44%) treated with conventional systemic drug. Overall follow-up was 3720 person-years. Of the 793, 20.5% (163) were diagnosed with LTBI before starting biological treatment. The rate of active TB for the exposed cohort was 145 cases × 100 000 patient-years (95% CI 54–389). No case of TB was found in the control group. Screening for LTBI was performed in 83% of the exposed sample.
Conclusion Patients with psoriasis who are exposed to biological treatment appear to be at greater risk for tuberculosis. In Spain, up to 20% of patients with psoriasis who are candidates for biological therapy have LTBI. There continues to be a significant percentage of errors in compliance with clinical guidelines.