Allergic response itchiness, swelling, running nose, watery eyes, coughing, wheezing, trouble breathing, hives, rashes, mucus production, or a more severe reaction anaphylaxis. Allergic responses and the severity vary from person to person. Many substances can trigger an allergic reaction. Common triggers of a reaction include foods, likes nuts, eggs, milk, gluten, fruit and vegetables; insect bites from bees or wasps (often a severe response occurs); environmental factors such as pollen, dust, mold, plants like grass or trees, animal dander; medications or chemicals. Some people experience an allergic response to cold or hot temperatures outside, jewelry or sunlight. There are daily treatments to
Allergic contact dermatitis primes and sensitizes the immune system for an allergic response, and an "elicitation phase", in which this response is triggered. As it involves a cell-mediated allergic response, ACD is termed a Type IV delayed hypersensitivity reaction, making it an exception in the usage of the designation "allergic," which otherwise usually refers to type I hypersensitivity reactions. Contact allergens are essentially soluble haptens (low in molecular weight) and, as such, have the physico-chemical properties that allow them to cross the stratum corneum of the skin. They can only cause their response as part of a complete antigen, involving their association with