Abstract Introduction Tuberculosis (TB) remains a major global health challenge, particularly impacting developing nations like Nepal. Effective TB management relies on the standard anti-tubercular therapy (ATT) regimen, typically consisting of isoniazid (H), rifampicin (R), pyrazinamide (Z), and ethambutol (E). While generally effective, adverse drug reactions (ADRs), especially cutaneous hypersensitivity reactions, can complicate treatment. These reactions range from mild pruritus and rashes to severe manifestations like Drug Rash with Eosinophilia and Systemic Symptoms (DRESS), often requiring ATT discontinuation and careful reintroduction. Identifying the causative agent is crucial for treatment completion and preventing resistance or relapse. This case highlights the management of drug-induced hypersensitivity in a young woman with cervical tubercular lymphadenitis. Case A 32-year-old woman presented with right-sided cervical lymphadenopathy, diagnosed as tubercular lymphadenitis via Fine Needle Aspiration Cytology (FNAC). She began first-line ATT (2HRZE/4HR). On day 11, she developed generalized pruritic rashes and mild shortness of breath, persisting until day 14, prompting ATT discontinuation and hospitalization. A stepwise drug rechallenge was initiated. Isoniazid was reintroduced first and tolerated well. Rifampicin followed, causing mild to moderate itching but no systemic symptoms. Pyrazinamide reintroduction resulted in itching, mild lip swelling, fever (101 °F), fatigue, and chest discomfort on day two. Pyrazinamide was stopped, and symptoms resolved with antihistamines. Ethambutol was then reintroduced, preceded by levocetirizine premedication, with no adverse reactions. Pyrazinamide was identified as the culprit. A modified HRE regimen was implemented for nine months, supplemented with pyridoxine and pre-dose levocetirizine. Discussion Drug-induced hypersensitivity, especially during the intensive phase of ATT, poses a significant challenge. This case demonstrates a systematic rechallenge approach for identifying the offending agent. Pyrazinamide is a frequently implicated drug in hypersensitivity reactions. Structured rechallenge protocols are crucial, requiring cautious implementation under supervision with access to emergency care. Premedication with antihistamines, like levocetirizine, can offer additional protection. Early recognition and modification of ATT prevented severe complications in this patient. The modified HRE regimen allowed safe treatment continuation without relapse or resistance risks. This case underscores the importance of vigilance for drug-induced hypersensitivity in TB patients and the value of individualized treatment strategies based on clinical judgment and evidence. This abstract is funded by: None
Chalise et al. (Fri,) studied this question.