Lessons learned from life-threatening respiratory and cardiac complications in diphtheria: A case report and literature review

Abstract: Diphtheria remains a serious threat and can cause life-threatening complications. We report the case of a 6-year-old girl with severe respiratory and cardiac involvement due to diphtheria. She presented with classic signs, including pseudomembrane, bull neck, lymphadenopathy, and respiratory distress. Corynebacterium diphtheriae var. mitis with a positive toxigenic strain was confirmed. Her condition worsened, requiring intensive care admission and high-flow nasal cannula support. She later developed ventricular tachycardia with hemodynamic instability, which was successfully treated with intravenous magnesium sulfate (MgSO 4 ). The patient recovered with antibiotics, antitoxin, and supportive care. This case highlights the potential for severe diphtheria complications, even with timely treatment. It also suggests a possible role for MgSO 4 in managing diphtheria-induced arrhythmias, though further research is needed. Early diagnosis, aggressive management, and continued vaccination efforts are critical to reducing diphtheria-related morbidity and mortality.