Complications

complications caused by diphtheria toxins

Both C. diphtheriae and C. ulcerans produce an exotoxin which may result in local tissue necrosis and toxaemia and systemic complications (when absorbed into the bloodstream) (1)

• the risk of complications is inversely proportional to the number of diphtheria toxoid vaccines received previously by the patient

Possible complications include:

• cardiac
• the risk of developing cardiac complications is associated with the extent and the severity of the bull neck and pseudomembrane coverage of the tonsils
• Diphtheric myocarditis
  • seen in around two thirds of patients
  • typically occurs 1-2 weeks after the onset of respiratory symptoms
  • associated electrocardiographic changes predicts a three- to fourfold higher mortality rate
• may also cause conduction disturbance, arrhythmias congestive heart failure and circulatory collapse
• neurological
• is also associated with the extent and the severity of the primary respiratory infection
• may cause regurgitation or aspiration and oculomotor and ciliary paralysis due to involvement of the soft palate, posterior pharyngeal wall and cranial nerves (2)

Reference:

• (1) Bonnet JM, Begg NT.Control of diphtheria: guidance for consultants in communicable disease control. World Health Organization. Commun Dis Public Health. 1999;2(4):242-9
• (2) Adler NR, Mahony A, Friedman ND. Diphtheria: forgotten, but not gone. Intern Med J. 2013;43(2):206-10