clinical features

Last reviewed 11/2022

The clinical features of diphtheria are the result of:

  • local infection and inflammation in the upper airway and pharynx
  • systemic effects of diphtheria toxin

After an incubation period is 2-6 days signs and symptoms develop within the respiratory tract:

  • pharynx and the tonsils are affected commonly with clinical manifestations such as sore throat, malasise, cervical lympadenopathy and low grade fever
    • enlargement of the cervical lymphnodes may result in oedema of the neck (a classical condition of "bullneck") (2)
    • in uncomplicated cases, the ‘bull-neck appearance’ resolves within around 2 weeks (1)
  • classical pseudomembrane on tonsils, tonsillar pillars, uvula, soft palate, oropharynx or nasopharynx may occur in many patients
    • initially it appear as a glossy and white membrane which may later develop into a grey colour with green or black patchy necrosis
    • attempts to remove the membrane result in bleeding
    • the extent of the membrane show a relationship to the severity of the symptoms (1)
    • pseudo-membrane may cause respiratory obstruction
    • may not be seen in people who have been vaccinated (3)
  • laryngeal involvement may result in hoarseness, dyspnoea, cough and stridor

In cutaneous infection, the presenting lesion is usually an ulcerative lesion called ‘ecthyma diphtheriticum’ which is seen usually on exposed parts, especially the legs, feet or hand.

  • lesions start as vesicles and quickly form small, clearly demarcated, and sometimes multiple ulcers (2)
  • these patients have a low risk of developing the pharyngeal form of the disease and the toxic manifestations (1)

Systemic absorption of the toxin may affect the myocardium, nervous and adrenal tissues, paralysis and cardiac failure (4).

Reference:

Related pages:

sore throat

bull neck

heart block

stridor (acute, childhood)

progressive bulbar palsy