What should you know about blood rash?

Surface bleeding often follows scratching, friction or cracked inflamed skin. Flat red, purple or brown dots that do not fade when pressed can reflect blood under the skin and deserve medical attention, particularly when newly widespread or accompanied by illness.

Look without scraping the area. Note whether blood sits on a cut surface, whether the spots are raised or flat, and whether gentle pressure makes redness fade. Also record itch, pain, blistering, bruising, fever, joint symptoms, a recent infection and any newly started medicine.

Atopic dermatitis and contact dermatitis can crack or bleed after scratching. Drug rash can present with widespread redness and may become serious when it involves blisters or moist surfaces. These conditions present in different ways, so appearance and timing guide the assessment.

For a small scratch, apply clean gauze with steady pressure, then rinse gently and cover any raw skin with a non-stick dressing. Avoid fragranced products, exfoliants and scratching. A plain moisturiser may protect dry intact skin, but do not apply unfamiliar medicines to open areas.

Take clear photographs and write down when the rash began and how it spread. Keep a list of medicines, supplements, recent illnesses and new skin products. Do not stop a prescribed medicine unless the prescriber or an emergency clinician advises it, except while following an existing emergency plan.

Seek emergency care for a non-blanching rash with fever, severe headache, neck stiffness, confusion, unusual sleepiness, breathing difficulty or rapid deterioration. Emergency assessment is also needed for facial or tongue swelling, faintness, widespread blistering, skin peeling, or painful sores of the mouth, eyes or genitals.

Prompt clinical review is appropriate for unexplained bruising, bleeding elsewhere, recurrent non-blanching spots, spreading warmth, pus, increasing pain or a rash that began after a new medicine.

Ask whether the marks represent inflammation, infection or bleeding beneath the skin, whether tests are needed, and which products are safe on broken skin. Mention nose or gum bleeding, heavy menstrual bleeding and easy bruising if present.