An allergy is an abnormally high sensitivity reaction to an ordinarily harmless substance. The immune system of an allergic person reacts when an allergen is absorbed into their body, treating the substance as a harmful invader, causing the white blood cells to begin producing IgE antibodies which attach themselves to mast cells. When this occurs it causes the body to release histamine, which can cause allergy symptoms -- watery eyes, itching, sneezing or a runny nose.

Contact dermatitis, eczema, and hives can be types of skin allergies.

Chemicals in cosmetics or lotions may also cause skin problems. The symptoms may occur right away, or take a few days to develop. These symptoms include swelling, burning, stinging, itching, and redness. Most of these reactions are caused by skin care products that are used on the face, hands, and body. Other causes include hair care products, including hair dye and permanent solution, and face makeup products.

Eczema may occur for unknown reasons or as a result of exposure to certain plants, foods, animals, nickel, rubber, soap products or dyes. This can produce itchy rashes and weeping blisters. This is a common problem with all jewelry made with nickel as a base metal.

Hives are another kind of skin response. They may occur as a result of changes in body temperature or stress. Hives are small, red, itchy swellings on the skin. They arise quickly and can last up to 48 hours. They appear in clusters which disappear as another cluster develops. Foods like chocolate, nuts, tomatoes, and berries are common causes of hives. Certain drugs such as aspirin, penicillin, and sulfa may cause hives, as well. Some people get hives simply by rubbing or scratching their skin.

No permanent cure exists for skin reactions. It is best to try and avoid the causes. It may help to change to hypoallergenic and fragrance free products. If contact dermatitis, eczema or hives do occur, they can often be treated with over the counter antihistamines such as Benadryl.