Soy Allergy

Soy allergy is a common food allergy, especially among children, in which the immune system launches an allergic reaction to soy or any products containing soy. It starts in early childhood and most of the children outgrow this allergy as they grow older.

Symptoms of soy allergy are generally mild, but in some rare cases it may be severe. Around 0.4% of the children are allergic to soy. Avoiding soy is difficult as it is found in many processed foods.

In most of the cases, symptoms of soy allergy are mild. The most common among them are:

• Hives, itching of skin, eczema
• Swelling in lips, tongue, or throat
• Runny nose, congestion
• Difficulty in breathing
• Stomach pain, diarrhea
• Vomiting
• Reddishness of skin
• Tingling in mouth

Very rarely, one might show severe, life-threatening reaction to soy. Severe symptoms of allergy is referred to as anaphylaxis. Anaphylactic reactions include:

• Block or swelling in throat 
• Rapid pulse
• Loss of consciousness
• Sudden drop in blood pressure

Anaphylaxis is life-threatening and the patient should be given medical attention immediately. 

Overreaction of the immune system to certain proteins present in soy is the main cause of soy allergy. Sensitive immune system of certain people consider the proteins as harmful and triggers the production of antibodies against them. 

On continued exposure, these antibodies activate the production of certain chemicals, called histamines, which lead to the typical symptoms of allergic reaction. Family history, age, and other forms of allergy are the main risk factors for soy allergy. 

Having a family history of hay fever, eczema, and asthma increases the chance of developing soy allergy. 

Soy allergy is more common among children, although it may develop at a later stage. People who are allergic to other food items like milk have higher risk of developing allergy to soy or soy products.

Allergens in soy may result in delayed food allergy. As name indicates, the symptoms are seen only after few hours of eating soy or soy products. This condition also improves with time. 

Even if you have a soy allergy, soy lecithin is safe to consume since the allergens have been removed.

Making a diagnosis of soy allergy is done during physical examination and by several tests.

Timing of symptoms is the major indicator of soy allergy. Doctors may perform a physical examination to rule out chances of any other condition that cause similar symptoms.

Skin test and blood test are also recommended to confirm this allergy:

• Skin test – In this test, a patch of skin is exposed to small amounts of allergen extract by pricking the skin with a probe. Inflammation of the skin in the test region within 15 minutes is a sign of soy allergy. The skin prick is usually done in upper arm or upper back. 
• Blood test – This test is recommended if skin test cannot be performed due to some reason like drug interaction. Blood test is used to measure the amount of specific antibodies against the suspected allergen. 

Increased levels of antibodies indicate soy allergy. It also gives a measure of sensitivity to the allergen. 

Several treatment methods exist for controlling the symptoms of soy allergy.

Strict avoidance of soy and soy-containing products is the best way to control the symptoms. Mild symptoms like hives and itching can be controlled by antihistamines. 

Severe, life-threatening symptoms are treated with an emergency shot of epinephrine. Injectable epinephrine is now available and can be carried along to avoid emergency situations.

Avoiding soy in food is the best way to prevent allergic symptoms. For infants, breast milk is a better option to prevent reaction. Read the labels carefully to avoid some foods that may contain soy products. 

Low-fat peanut butter, canned soup, some crackers, and energy bars may contain soy. One should completely avoid tofu, natto, tempeh, shoyu, edamame, vegetable oil, and miso. 

Beware of food labels that show glycine max, hydrolyzed vegetable protein, textured vegetable protein, monodiglyceride, and monosodium glutamate. These products may also contain soy products.

Many of the alternative remedies for soy allergy support the immune system and prevent inflammation. Vitamin and zinc supplements aid in improving the functioning of immune system. 

Quercetin supplement and turmeric helps the body during an allergic reaction. Bromelain and probiotics help in digestion. Lycopodium is recommended in homeopathy for controlling soy allergy.

Lifestyle modifications are necessary in order to cope with soy allergy.

Letting others know of the allergy is very important to take preventive measures.

Wearing a bracelet help other know that you are allergic to soy.

Always carry epinephrine shot for emergency use.

There are several complications associated with soy allergy. These include:

• Allergic reaction can affect the way one eats food and cause anxiety.
• In some rare cases, soy allergy may cause anaphylactic reactions.