Red itchy rash on the arms and legs

Dry rough patches may fit Atopic Dermatitis, while exposure to plants, products, or fabrics can cause Contact Dermatitis. Heat Rash tends to occur where sweat collects. Thick, well-defined scaly plaques can occur with Psoriasis. Ringworm may be round or ring-shaped with a more active scaly edge. A rash after a new medicine may be a Drug Rash. Scabies can cause severe night itching with spots in several areas. These conditions can overlap in appearance, so a clinician may need to inspect the skin closely.

Use a gentle cleanser, lukewarm water, and a fragrance-free moisturiser. Avoid new creams, detergents, plants, and rough fabrics until the pattern is clearer. Keep cool if heat worsens itching, and use a cool compress rather than scratching. Wash hands after touching the rash and avoid sharing towels. Note new medicines, outdoor activities, insect exposure, fever, scaling, and whether the rash is spreading.

Seek emergency help for breathing difficulty, swelling of the face or tongue, faintness, or blistering and peeling skin. Arrange prompt review for fever, painful skin, pus, red streaking, fast spread, or involvement of the eyes or mouth. A persistent or recurrent limb rash also deserves an examination, particularly after a new medicine.

Ask what the shape and scale suggest, whether a medicine or exposure could be responsible, which treatments are suitable for the affected sites, and how to recognise infection or a serious reaction.