A soy allergy occurs when the body's immune system is incorrectly triggered by, and reacts to, foods containing soy protein. The first exposure to soy may not cause symptoms, but the immune system is being "triggered" to think that soy-containing foods are harmful. This first response is remembered by the immune system due to a special protein, known as the antibody IgE; subsequent exposures to soy result in the release of several chemicals, including histamine. These chemicals cause the symptoms of the allergic reaction. Patients with such an allergy may benefit from several medications.
Topical Creams, Lotions, or Ointments
The National Institute of Health website, Medline Plus, informs patients that in cases of a mild and local reaction to soy protein exposure--for instance a small area of hives on the face after drinking a cup of soy milk--a simple treatment such as a lotion or cream to soothe the itchiness may be all that is needed to relieve the discomfort. For example, ointments, lotions, or creams containing the medication hydrocortisone may relieve itchiness; at the 0.5 percent and 1 percent concentrations, hydrocortisone is available without a prescription. It is important to note this treatment should only be used if the reaction is mild and limited to a small area of the skin. If the hives are all over the body, or if other symptoms also occur after exposure to soy, other treatments may be more helpful.
Antihistamines
According to the Mayo Clinic article on soy allergy, the only way to truly treat a soy allergy is by avoiding any foods or drinks that may contain soy proteins. Besides the obvious sources of soy--for instance, a soy-based formula for babies, soybeans, or soy milk drinks for adults--foods such as tofu, miso soup, and tempeh contain soy. Vegetable oil is often actually soybean oil, and certain additives, such as MSG, may be a hidden source of this allergen. However, despite every effort to avoid ingesting soy-containing products, a person with a soy allergy may still be exposed. In such cases, he may experience symptoms such as itching, hives, swelling of the lips, or a tingling sensation in the mouth. Taking an over-the-counter antihistamine medication, such as Benadryl, may help relieve some of these milder symptoms of soy allergy.
Epinephrine
In rare cases, people with a soy allergy develop severe, life-threatening symptoms when exposed to soy. This kind of reaction is called an anaphylactic reaction and, according to the Food Allergy and Anaphylaxis Network, this is rarely seen in response to soy. However, it can occur, and in such cases, patients should carry epinephrine with them. The EpiPen and and the EpiPen Jr. are portable pen-like containers that are filled with injectable epinephrine. If a person with a severe soy allergy is unknowingly exposed to soy and begins showing symptoms such as difficulty breathing, increased heart rate, or loss of consciousness, the EpiPen may be a life-saving medication for him.
