Diphtheria is caused by the Gram positive bacterium Corynebacterium diphtheriae

Pathophysiology

• releases an exotoxin encoded by a β-prophage
• exotoxin inhibits protein synthesis by catalyzing ADP-ribosylation of elongation factor EF-2

Diphtheria toxin commonly causes a 'diphtheric membrane' on tonsils caused by necrotic mucosal cells. Systemic distribution may produce necrosis of myocardial, neural and renal tissue

PC

Possible presentations

• recent visitors to Eastern Europe/Russia/Asia
• sore throat with a 'diphtheric membrane' - grey, pseudomembrane on the posterior pharyngeal wall
• bulky cervical lymphadenopathy
  • may result in a 'bull neck' appearanace

Investigations

• culture of throat swab: uses tellurite agar or Loeffler's media

Management

• intramuscular penicillin
• diphtheria antitoxin