Outcomes of reintroducing anti-tuberculosis drugs following cutaneous adverse drug reactions

BACKGROUND: Data regarding outcomes of tuberculosis (TB) associated cutaneous adverse drug reactions (CADR) are limited. The re-introduction of first-line anti-tuberculosis drugs after CADR is controversial and management poorly defined. METHODS: We retrospectively reviewed the records of 298 patients with CADR admitted to a tertiary dermatology ward in Cape Town, South Africa. RESULTS: TB-associated CADR was diagnosed in 65 of 298 patients. Of these, 60/65 (92%) were human immunodeficiency virus (HIV) infected (median CD4 count 107 cells/mm(3)). Anti-tuberculosis drugs were reintroduced in 46/65 (71%) patients, of whom 23/46 (50%) developed re-introduction reactions. The most frequent re-introduction reactions were itch in 11/23 (48%) and hepatitis in 9/23 (39%) patients. Of the 23 re-introduction reactions, 13 (57%) were mild, six (26%) moderate and four (26%) severe. Among those with reintroduction reactions, rifampicin (RMP) was the offending drug in 13/23 (57%), isoniazid in 5/23(22%), pyrazinamide in 3/23 (13%), and ethambutol, streptomycin and ofloxacin each in 1/23 (4%) cases. Lack of previous TB treatment and re-challenge with RMP were independently associated with the likelihood of reintroduction reactions. CONCLUSIONS: In this high TB burden setting, although re-introduction reactions are common, the majority are non-life-threatening. All first-line anti-tuberculosis drugs can cause CADR, and RMP is more commonly implicated than previously reported. These data guide the management of anti-tuberculosis drug-associated CADR in high HIV prevalence settings.