What should you know about itchy rash all over body?

Widespread itch may occur with Atopic Dermatitis, an allergic or irritant Contact Dermatitis, or a Drug Rash after starting or changing a medicine. Heat Rash and Intertrigo usually favour warm, moist or rubbing areas, although irritation can feel extensive. Psoriasis can affect several body sites and may have thick, scaly patches. Ringworm often forms separate scaly areas, while Scabies may cause intense night-time itch and affect people who share close contact. The rash pattern and examination help separate these possibilities.

Write down when the rash began, any new medicine or supplement, recent illness, travel, food, detergent, cosmetic, or contact with an itchy person. Use lukewarm water, fragrance-free cleanser, and a plain moisturiser. Keep the room cool, wear loose clothing, and avoid scratching. Do not stop a prescribed medicine without advice, but contact the prescriber promptly if the rash followed a new treatment. Avoid sharing towels, clothing, or bedding until a contagious cause has been considered.

Call emergency services for breathing difficulty, throat or tongue swelling, faintness, or rapidly developing widespread hives. Seek urgent assessment for fever with a painful rash, blisters, skin peeling, purple or bruised-looking spots, sores in the mouth or eyes, facial swelling, or feeling acutely unwell. Arrange a timely appointment when the rash follows a new medicine, keeps spreading, disturbs sleep, or does not settle with gentle care.

Could a medicine, infection, eczema, fungal condition, or scabies explain this distribution? Do I need tests or a full skin examination? Which treatments are safe while the cause is being confirmed? Should people at home be checked?