Tuberculosis infection versus anti-tumor necrosis factor therapy: screening challenges in psoriatic patients

OBJECTIVES The aim of this study was to analyze the performance of the tuberculin skin test (TST) for screening and monitoring patients treated with anti-tumor necrosis factor agents, in a high-incidence area. METHODS A 3-year retrospective study was carried out on 268 subjects. The study included 68 patients with moderate-to-severe psoriasis, screened for latent tuberculosis infection (LTBI) and subjects without psoriasis (100 adults and 100 children) with close contact with infected individuals. RESULTS Positive tuberculin skin test (TST) results (induration >5 mm) were observed in 70.5% (48/68) of patients with psoriasis, higher than those observed in subjects with suspicion of tuberculosis or with close contact with infected individuals: 51% (51/100) in the adult group and 30% (30/100) in the children group. CONCLUSIONS These results show that the prevalence of LTBI evaluated with the TST in the psoriatic group is higher than in subjects without psoriasis. LIMITATION The positive reactions were not confirmed by other verification methods.