Toxidermia Secondary to Anti-Tubercular Therapy: A Cross Sectional Study

Abstract

Introduction: Tuberculosis (TB) is a major global public health problem and leading cause of death among communicable diseases in India. Anti 
tubercular therapy (ATT) is associated with various adverse drug reactions including diverse presentation of cutaneous adverse drug reactions (CADRs) also known as toxidermia, ranging from mild to life threatening sequelae. Re challenge remains the only option to restart the therapy safely with other primary ATT drugs. 

Objectives:  To study the epidemiological profile, various CADRs, histopathological features, identify the offending drug and reinstitution of safe ATT. Materials and Methods: This was a cross-sectional study conducted at tertiary care centre. Patients who were diagnosed with tuberculosis of any type and on ATT with CADRs were included in the study. Data collection included demographic characteristics, type of TB, ATT regimen, pattern of drug rash, offending drugs, histopathological features, laboratory parameters and reinstitution of ATT after re challenge. tubercular drugs in 2(25%) patients.

Results: Among 32 adult patients, male to female ratio was 1:1.3 and mean age was 45 years. Clinical diagnosis of CADRs was confirmed histopathologically. The most common type of TB observed was Pulmonary, (n= 21, 65.6%) followed by extra pulmonary (n=11, 34.4%). Among 32 cases of CADRs, Maculopapular rash was the most common 15(46.87%) type of cutaneous eruptions followed by lichenoid drug rash in 6(18.75%), urticarial in 5(15.63%), 4(12.5%) had generalised xerosis and 2(6.25%) had severe CADRs in the form of erythema multiforme1(3.15%) and DRESS syndrome1(3.15%). Patients with milder forms of CADRs were continued ATT with concomitant topical treatment for cutaneous lesions. Re-challenging was performed as per the institution’s protocol in 8 patient who gave consent. Ethambutol was the most common 6(75%) offending drug followed by other first line anti 

Conclusion: CADRs to ATT is like a poisoned chalice, as stopping ATT and treating CADRs with systemic steroids can aggravate underlying TB. Re
challenge with ATT will help in sniffing out the culprit drug and reintroduction of safer alternative regimen.