Hi Thanks for the query Red rashes on the upper body with severe itching seems to be most probably due to allergic reaction causing allergic dermatitis. It occurs when skin comes in contact with certain agents that your body is allergic to like skin cosmetics, detergents, soaps, fragrances,leather, latex, poison ivy etc. I would suggest you to consult an Allergist and get evaluated and a thorough clinical evaluation and investigations like allergic tests like Patch test, RAST test, food challenge test etc can help in diagnosis and treatment can be done accordingly. The tests will help in ruling out the exact cause of the allergen and once you know the cause of the allergic reaction you can avoid exposure to it to prevent allergy attack. The allergist can advise to oral anti allergic as well as ineluctable steroids for relief. As of now you can take anti-allergies like Levocetrizine, Allegra to control the itching and swelling. Do cool compresses. Application of calamine lotion can help in soothing the skin. Hope this helps Regards