Paradoxical Cervical Lymphadenitis During Anti-tubercular Therapy in an Immunocompetent Young Female: A Diagnostic Pitfall

A paradoxical reaction (PR) in tuberculosis (TB) is defined as clinical and/or radiological worsening of pre-existing tuberculous lesions or the appearance of new lesions during appropriate anti-tubercular therapy (ATT), despite initial improvement and in the absence of treatment failure, drug resistance, poor adherence, or superinfection. Although more commonly described in HIV-infected or disseminated TB cases, PR can also occur in immunocompetent individuals and may be misinterpreted as disease progression. We report a case of a 19-year-old immunocompetent female receiving standard first-line ATT for sputum-positive pulmonary TB who developed progressive, painless right cervical lymphadenopathy two months after initiation of therapy. Ultrasonography revealed a large necrotic cervical mass suggestive of a tubercular abscess. Repeated ultrasound-guided fine needle aspiration cytology was inconclusive. Given the absence of systemic symptoms, treatment adherence, and lack of evidence of drug resistance, a diagnosis of PR was considered. In conclusion, recognition of PR is essential to prevent unnecessary modification of ATT, escalation to second-line therapy, or invasive procedures. Clinicians should maintain a high index of suspicion for PR in compliant patients presenting with new or enlarging lesions during the early months of treatment.