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

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 (MgSO4). 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 MgSO4 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.