Red dots in a rash on the arms

Check whether the dots fade briefly when pressed with a clear glass or fingertip. Also note whether they are raised, centred on hair follicles, scaly, ring-shaped, bruised-looking, or grouped in areas exposed to a product or heat. Contact Dermatitis and Heat Rash can produce red spots; Atopic Dermatitis and Psoriasis may create broader inflamed or scaly areas. Ringworm can form an expanding ring, and a Drug Rash may begin after a new medicine. Red dots alone cannot confirm any one condition.

Write down when the spots appeared and whether new medicines, illness, sun exposure, exercise, shaving, detergents, or cosmetics preceded them. Photographing the area can help a clinician compare changes.

Use gentle cleansing and a fragrance-free moisturiser. Avoid scratching, hot showers, tight sleeves, new topical products, and vigorous rubbing. Do not apply multiple active creams before the cause is assessed, because they can change the appearance or irritate the skin. If a medicine may be involved, contact the prescriber promptly for advice rather than changing essential treatment on your own.

Seek urgent care if the dots do not fade with pressure and you feel feverish, weak, confused, short of breath, or unusually unwell; also seek help for facial swelling, blistering, skin peeling, or sores in the mouth or eyes. Prompt assessment is appropriate when spots spread quickly, become painful, look like bruises, or appear after a new medicine. Arrange routine review for dots that persist, recur, or change.

Do the dots blanch, and does that change the level of concern? Could a medicine, exposure, follicle irritation, or infection explain them? Should I have blood tests or a skin test? Which changes mean I should seek urgent help?