Rash and skin itching
Patient education
- Similar-looking rashes have different causes
- Skin colour changes the appearance
- Use the right treatment for the cause
What it is
A rash is a change in skin colour, texture or sensation. Infection, mites, eczema, medicines and allergies can all cause it. Treatment depends on the cause; a similar appearance does not mean the same disease.
When to seek urgent care
There is trouble breathing or swelling of the lips or tongue; a rapidly spreading painful rash with fever; purple spots that do not fade under pressure with illness; or blistering, peeling skin, or sores in the eyes or mouth, especially after a new medicine.
How it shows
Itching, scaling, bumps, blisters, crusts or tender swelling. Inflammation can appear red, purple, grey or darker than surrounding skin. Note where it started, whether it is spreading, new products or medicines, and whether others at home itch.
What to do
Arrange assessment for a persistent, spreading or painful rash. Avoid sharing towels and do not start a steroid or mixed cream for an unexplained rash. The photos below show examples, not a test for diagnosing your skin.
Skin-lightening creams and strong steroid creams bought without advice make many rashes considerably worse and can damage the skin permanently.
Common infections and infestations
Ringworm is a fungal infection, not a worm. It may form itchy, scaly patches with an expanding edge. On the scalp it can cause scaling and broken hairs or patches of hair loss. The rash is not always a neat ring.
Scabies is caused by tiny mites and often itches most at night. Bumps or burrows may occur between fingers, around wrists or at the waist. Close contacts can be affected before they notice symptoms. The clinician may examine the skin or take a scraping.
Impetigo is a bacterial infection that can cause weeping sores and crusts, often around the nose or mouth. It needs assessment for appropriate antibiotic treatment. Eczema and contact reactions can also cause rashes, without being infections.
On darker skin, inflammation may look purple, grey, brown or darker than nearby skin rather than bright red. Changes in warmth, swelling, tenderness and texture matter too. A photograph cannot confirm a diagnosis.
Treatment and preventing spread
Ringworm needs antifungal treatment. Scalp infection usually needs prescription medicine taken by mouth; skin cream alone is not enough. Avoid steroid creams or mixed 'all-purpose' creams on a suspected fungal rash unless a clinician advises them, as they can mask or worsen infection.
For scabies, household members and close contacts usually need treatment at the same time. Follow instructions for clothing, bedding and towels. Itching can continue after treatment, but new burrows or ongoing symptoms need review. Do not share towels, combs or clothes, and keep skin clean without harsh scrubbing.