Allergic contact dermatitis occurs when the skin comes into direct contact with an allergen. ... Touching clothing, pets, chemicals, soaps, and substances such as poison ivy or cosmetics can trigger allergic reactions. Food allergies can also cause the skin to itch.The ever growing pollution has caused allergic responses a regular issue especially in the urban life of human being. Allergy is a hypersensitive reaction of the immune system produced by several origins such as environmental factors, drugs, foods etc. The Journal of Allergy & Therapy presents a spectrum of exciting information on various approaches adopted and their possible outcomes in allergy research including new strategies in diagnosis, therapy and prevention of allergic diseases. If you have red, bumpy, scaly, itchy or swollen skin, you may have a skin allergy. Urticaria (hives) are red, itchy, raised areas of the skin that can range in size and appear anywhere on your body. ... When certain substances come into contact with your skin, they may cause a rash called contact dermatitis.