Hypersensitivity reactions to multiple anti-tuberculosis drugs.

Objective This study aimed to evaluate hypersensitivity reactions to anti-tuberculosis (TB) drugs. Methods We retrospectively compared the clinical manifestations and treatment outcomes of single and multiple drug hypersensitivity reactions (DHRs). Results Twenty-eight patients were diagnosed with anti-TB DHRs using oral drug provocation tests. Of these 28 patients, 17 patients (60.7%) had DHRs to a single drug and 11 (39.3%) had multiple DHRs. The median age of patients was 57.5 years (interquartile range [IQR], 39.2-73.2). Of the total patients, 18 patients (64.3%) were men. The median number of anti-TB drugs causing multiple DHRs was 2.0 (IQR 2.0-3.0). Rifampin was the most common drug that caused DHRs in both the single and multiple DHR groups (n = 8 [47.1%] and n = 9 [52.9%], respectively). The treatment success rate was lower in the multiple DHR group than in the single DHR group; however, the difference was not statistically significant (81.8% vs. 94.1%; P = 0.543). Conclusions Multiple anti-TB DHRs were common in all patients who experienced DHRs, and rifampin was the most common causative drug. The treatment outcomes appeared to be poorer in patients with multiple DHRs than in those with single DHRs.