Spectrum of anti tubercular therapy induced cutaneous adverse drug reactions and its management through rechallenge: A prospective study at a Tertiary Care Centre

Introduction: The use of multi-drug regimens including 1st and 2nd line anti tubercular drugs in management of tuberculosis (TB) has been associated with undesirable adverse drug reactions including cutaneous one. Re-challenge remains the only option to restart the safe therapy and combat the tuberculous infection simultaneously.

Materials and methodology: This cross-sectional study was conducted via prospective review of outpatients as well as indoor patients who presented with cutaneous adverse drug reactions to ATT between March 2020 and March 2021. Data were analysed regarding demographic profile, site of TB, ATT regimen, pattern of cutaneous lesions, offending drugs, past history of drug allergy, and reinstitution of ATT after re-challenge.

Results: Out of total 56 registered tubercular patients presented with cutaneous adverse drug reaction 30 were females (53.57%). The most common site of TB was pulmonary followed by cervical lymph node TB. The three most common adverse drug reaction detected were maculopapular rash 32 (57.1%) followed by lichenoid drug eruptions in 6 (10.7%) and urticaria in 2 (3.6%). Ethambutol was found to be common offending drug followed by other first line anti-tubercular drugs. 5 patients developed multiple drug hypersensitivity on re-challenging and have to introduce steroids along with ATT.

Conclusion: Adverse cutaneous drug reactions to ATT is like a double-edged sword as stopping ATT and starting treatment with systemic steroids can further flare up the infection with increased risk of disseminated and multidrug resistant tuberculosis. Re-challenge was found out to be safest way in identifying culprit drug and hence to restart a safer alternate ATT regimen for better management.