Diagnosing diphtheria

Diphtheria may cause a sore throat, fever, swollen neck glands, weakness and a thick grey or white coating over the throat or tonsils. The coating can bleed if disturbed. Hoarseness, noisy breathing or difficulty swallowing can signal swelling around the airway. Tell the clinician about contact with someone unwell, recent travel and your vaccination history.

A clinician examines the throat and breathing, then takes a swab from the nose or throat for laboratory testing. Treatment and infection-control decisions may begin before results return because waiting can be unsafe when diphtheria is suspected. Close contacts may also need assessment and preventive care.

Seek urgent medical advice and avoid close contact with others until a clinician gives instructions. Do not scrape or try to remove a throat coating. Cover coughs, wash hands and do not share cups, utensils or towels. Bring vaccination records if available. Prescribed antibiotic treatment may be used to clear the bacteria, while contacts may need testing and vaccination review.

Call emergency services for difficulty breathing, blue or grey lips, inability to swallow saliva, rapidly increasing neck swelling, severe weakness, fainting or confusion. A severe sore throat with a membrane-like coating needs prompt assessment, especially when immunisation is incomplete or unknown.

Ask whether a throat swab is needed, whether you should isolate, and which household or workplace contacts need advice. Check whether your vaccination record is complete, how prescribed treatment should be taken, and which breathing or swallowing changes require emergency help.