An acute infectious disease of the respiratory tract, rarely seen in the UK since the introduction of immunisation in 1940, it is still an important cause of disease in many parts of the world. The infection is caused by Corynebacterium diphtheriae and is spread by water droplets. It usually presents with a sore throat, and there is a slightly raised membrane on the tonsils. There may be some swelling of the neck and lymph nodes, though the patient's temperature is seldom much raised. Occasionally the disease occurs in the eye or genital tract, or it may complicate lesions of the skin. More serious consequences follow the absorption of TOXINS which damage the heart muscle and the nervous system.
Provided that the patient is not allergic to horse serum, an injection of the antitoxin is given immediately and a course of penicillin started (or erythromycin if the patient is allergic to penicillin). Diphtheria may cause temporary muscle weakness or paralysis, which should resolve without special treatment; if the respiratory muscles are involved, however, artificial ventilation may be necessary.
It is recommended that all infants should still be immunised against diphtheria; (see IMMUNISATION).