What should you know about the etiology of diphtheria?

Corynebacterium diphtheriae can colonise the upper airway or, less often, the skin. Some strains release a toxin that damages local tissue and may affect organs elsewhere in the body. A thick grey coating in the throat can form, but not everyone has the same symptoms.

A sore throat is a possible presentation of diphtheria, but a sore throat alone does not establish the diagnosis. Vaccination lowers the risk of severe disease, while close contact with an infected person can allow transmission, especially when protection is incomplete.

Arrange urgent medical assessment for suspected diphtheria and tell the service before arriving so infection-control steps can be prepared. Avoid close contact, sharing cups or utensils, and handling used tissues. Do not rely on leftover medicines; a clinician may arrange testing, antibiotics and treatment for close contacts.

Check whether household members are up to date with recommended immunisations. Follow public-health or clinical advice about isolation and returning to school or work.

Seek emergency help for noisy or difficult breathing, inability to swallow saliva, rapidly worsening throat swelling, bluish lips, confusion or marked weakness. Diphtheria can obstruct the airway and toxin-related illness can worsen beyond the original throat symptoms.

Ask whether testing is needed, how long to avoid close contact, which treatment is appropriate, and whether household contacts need assessment or preventive care. Ask when immunisation should be reviewed after the illness or exposure.