Food allergies and food additive reactions can cause a wide range of symptoms. Some individuals may experience a digestive response, in which they are unable to properly digest these substances. People who are hypersensitive may experience hives, nausea, vomiting, abdominal cramps, and, in severe cases, anaphylaxis.

Skin Allergies

Angioedema. Angioedema or hives is the sudden appearance of swollen areas of the skin, mucous membrane, and occasionally, the internal organs. It most often occurs on the hands, feet, and face. If the angioedema occurs in the throat, normal breathing or swallowing can be blocked, causing an emergency situation.

Allergic Contact Dermatitis. A reaction that occurs when the skin comes in contact with plants, such as poison ivy; metals; latex; or cosmetics. The reaction usually occurs within one to three days and can last for a week or longer. The skin becomes red, itchy, inflamed, and blistered.

Atopic Dermatitis. Known as eczema, atopic dermatitis is an allergic skin disorder. Flare-ups may be caused by food or inhaled allergens to which the patient is allergic.

Medication Allergies

Some individuals are allergic to prescribed and/or over-the-counter medications, most commonly penicillin, ibuprofen, and blood pressure medicine. Undiagnosed medication allergies can cause anaphylaxis. In subtler cases, medication allergies can contribute to asthma attacks in adult asthmatics.