What should you know about diphtheria side effects?

Diphtheria bacteria can produce a toxin that injures tissues beyond the original infection. A thick coating in the throat may narrow the airway and make swallowing difficult. As illness progresses, inflammation or toxin effects can disturb heart rhythm, heart pumping or nerve signals. Weakness, a change in the voice, difficulty moving the palate, or trouble using the arms and legs deserves medical assessment. A sore throat can occur with many illnesses, so it does not by itself identify diphtheria.

Some people have skin diphtheria, with slow-healing sores or ulcers. The infection can spread to close contacts through respiratory droplets or contact with infected secretions, making prompt clinical advice important.

Contact a clinician promptly if diphtheria is suspected, and avoid close contact until you receive advice about testing and infection precautions. Treatment may include diphtheria antitoxin and antibiotics; antibiotics help clear the bacteria, while antitoxin addresses toxin that is already circulating. Do not stop prescribed medicine early. Clinicians may assess household contacts and recommend preventive treatment or vaccination when appropriate. Read more about Antibiotic Treatment and Childhood Immunisation.

Seek emergency help for noisy or difficult breathing, blue or grey lips, inability to swallow saliva, rapidly worsening neck swelling, fainting, chest discomfort, a very fast or irregular heartbeat, or new severe weakness. These signs can reflect airway obstruction or toxin-related complications and need immediate assessment. A person with suspected diphtheria should not wait for symptoms to become severe before contacting a healthcare service.

Ask which symptoms should trigger emergency help, whether you need isolation precautions, how contacts will be assessed, and when follow-up is needed for heart or nerve effects.