Successful drug desensitization in patients with delayed-type allergic reactions to anti-tuberculosis drugs

Abstract

Objective: To evaluate the outcomes of anti-tuberculosis drug desensitization. Methods: This was a retrospective study. Inclusion criteria were as follows: age >18 years, documented tuberculosis infection, a previous cutaneous allergic reaction to anti-tuberculosis drugs, and having undergone drug desensitization between January 2003 and March 2014. The definition of allergic reaction to anti-tuberculosis drugs included (1) a temporal relationship between drug use and the allergic reaction; (2) improvement in the allergic reaction after drug withdrawal; (3) recurrence of the allergic reaction after reintroduction of only the offending drug; and (4) absence of other causes. Results: A total of 19 desensitization procedures were performed. The drugs used for these procedures were isoniazid (n = 7), rifampicin (n = 6), or ethambutol (n = 6). Of note, severe allergic reactions (Stevens–Johnson syndrome (n = 4), erythema multiforme (n = 3), and drug rash with eosinophilia and systemic syndrome (n = 1)) were included. All patients underwent resolution of the previous allergic reactions before desensitization. The median duration of desensitization was 18 days. The success rate was 78.9%. The allergic reactions following failed desensitization were not severe; most were maculopapular rashes. Conclusions: The desensitization protocol for anti-tuberculosis drugs was associated with a high success rate, and the individuals who failed desensitization experienced mild allergic reactions. Keywords: Desensitization, Antituberculosis, Steven-Johnson syndrome, Allergic drug reaction, Tolerance induction, Drug allergy