Since the introduction of a vaccine in 1942, diphtheria has become very uncommon in the UK. Today, all children born in the UK are offered the vaccine as part of their primary childhood immunisations (it is the “D” of the DTP+Hib vaccine). The few cases seen in the UK now are in non-immunised patients who usually acquire their infection in Eastern Europe and the former Soviet Union as vaccination there is no longer routine practice.
Diphtheria most commonly affects the upper respiratory tract but it can affect any mucous membrane including the conjunctivae, vagina or ear. Diphtheria can also cause skin infections. Asymptomatic colonisation is more common than infection.
The respiratory features of the classical presentation of diphtheria are:
- Severe sore throat
- Painful cervical lymphadenopathy
- Swelling of the neck leading to a “bull neck” appearance
- Asymmetrical adherent greyish white membranes (pharyngeal membranes), with surrounding inflammation, which may extend into the trachea and cause airway obstruction (diphtheria looks more like opaque Clingfilm or plastic food wrap whereas in tonsillitis there is pus on the tonsils and no membrane, see image below)