What should you know about pharyngeal diphtheria?

It is caused by toxin-producing Corynebacterium diphtheriae bacteria. The infection may form a thick grey or white coating over the tonsils, throat, or nose. Trying to remove this coating can make the tissue bleed, so it should be assessed by a clinician.

The infection can cause a sore throat, fever, weakness, swollen glands in the neck, and a hoarse voice. Neck swelling may give a thickened appearance. Breathing or swallowing can become difficult if the throat becomes swollen or obstructed.

Diphtheria toxin can damage tissues beyond the throat, including the heart and nerves. A person can spread the bacteria through respiratory droplets or close contact, and sometimes through contact with infected secretions or skin lesions. Vaccination lowers the risk but does not replace assessment when concerning symptoms are present.

Contact urgent medical services if diphtheria is suspected, and tell the service before arriving so suitable infection-control measures can be arranged. Keep away from close contact with household members until a clinician gives instructions.

Do not share cups, utensils, towels, or toothbrushes. Cover coughs and sneezes, wash hands often, and avoid touching the throat coating. A clinician may take a throat or nose swab and may start diphtheria antitoxin and antibiotics promptly when the clinical picture warrants it; treatment should not be delayed while waiting for every result.

Close contacts may need assessment, testing, preventive antibiotics, and an immunisation review. Follow public-health instructions and complete any prescribed treatment. More information about [Antibiotic Treatment](/treatments/medical-management/antibiotic-treatment/) and [Childhood Immunisation](/treatments/preventive-care-and-vaccination/childhood-immunisation/) may help you prepare for that discussion.

Seek emergency help immediately for noisy or difficult breathing, bluish lips, inability to swallow saliva, rapidly increasing neck swelling, faintness, confusion, or severe weakness. These signs can indicate airway narrowing or serious systemic illness.

Arrange urgent assessment for a sore throat with a thick throat coating, fever, swollen neck glands, or recent close contact with someone who has suspected or confirmed diphtheria. A [Sore Throat](/symptoms/sore-throat/) can have many causes; the coating, breathing symptoms, exposure history, and vaccination history help clinicians judge the risk.

Ask whether throat and nose testing is needed, whether antitoxin or antibiotics should begin now, and how long you should avoid close contact. Ask which household or workplace contacts need evaluation and whether your immunisation record needs updating.