What should you know about diphtheria skin?

Skin diphtheria is an infection of broken or damaged skin. A sore may begin as a blister or shallow lesion and develop into an ulcer covered by a greyish material or crust. It may heal slowly and can be surrounded by redness, swelling or tenderness. The appearance overlaps with other skin infections, so looking at a sore is not enough to confirm the cause.

The bacteria can be present in wound fluid and spread through direct contact. Some people also have throat infection, with a sore throat or a coating in the throat. A clinician may take a swab from the wound and consider testing from the throat when symptoms suggest wider infection.

Arrange prompt medical assessment for a persistent, spreading or unusual ulcer, particularly after travel or contact with a suspected case. Keep the wound clean and covered, wash hands after touching dressings, and do not share towels, clothing or personal items. Avoid picking the crust. Clinicians may prescribe antibiotics and assess whether contacts need advice, testing or preventive care. Antibiotic Treatment and Childhood Immunisation provide related information.

Seek urgent care if redness spreads quickly, pain or swelling becomes severe, fever develops, the person feels faint or confused, or the wound is near the eye or mouth. Emergency help is needed for breathing difficulty, trouble swallowing, or swelling of the neck. These features may indicate infection beyond the skin or a more serious airway problem.

Ask whether the lesion needs a swab, how to dress it safely, when it is safe to return to close contact, and whether household members need evaluation or vaccination advice.