Asian Journal of Case Reports in Medicine and Health

Diphtheria is a toxin-mediated infectious disease caused by Corynebacterium diphtheriae, which remains a public health concern in regions with inadequate immunization coverage. We report a case of a 21-year-old partially vaccinated male who presented with dysphagia, throat pain, and fever. Clinical examination revealed grade 3 tonsillar hypertrophy with an adherent whitish pseudomembrane, raising strong suspicion of diphtheria. Laboratory investigations showed neutrophilic leukocytosis and elevated inflammatory markers. The patient was promptly admitted in isolation and started on diphtheria antitoxin (DAT) and erythromycin prior to microbiological confirmation. Throat swab culture later confirmed Corynebacterium diphtheriae. The patient received 120,000 IU of DAT following desensitization and was closely monitored for systemic complications. He showed progressive clinical improvement with complete resolution of symptoms and pseudomembrane by day 14, and no evidence of cardiac involvement on serial monitoring. This case highlights the importance of early clinical recognition and immediate initiation of antitoxin therapy without waiting for laboratory confirmation. Maintaining high vaccination coverage and ensuring booster doses in adults are essential to prevent re-emergence of diphtheria.