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This information was reviewed and approved by Bruce J. Lanser, MD, MPH (7/31/2015).

Frequently asked questions concerning food allergies. 

Question: My 12-year-old son is allergic to peanuts. Depending on the wind and amount of peanuts being eaten at a baseball game, he can suffer from nasal congestion/runny nose and nasal itching. Could a nasal spray assist or aid in prevention of the allergy?

Answer: Peanuts as a cause of your son's allergy at a ballgame is possible, but highly unlikely. Studies have been performed to deermine how much peanut protein can become airborne or aerosolized, and it is a very small amount (often too small to cause a reaction), and it does not travel far. Other causes of his symptoms may be dust, grass or smoke sensitivities. Pre-treatment with an allergy medication may help what are more likely to be allergy symptoms.

Question: I have always had normal nasal allergy symptoms but this year I have also developed asthma and food allergies. Lately, as trees have been starting to bud, I have developed severe skin "itchiness." I am very sensitive to various fabrics - cotton seems to be the only thing I can tolerate. Is this a typical allergic response? What can I do to stop the itching?

Answer: Many people with nasal allergy (allergic rhinitis) and springtime allergies develop significant symptoms such as itchy skin. Another phenomenon, known as pollen-food allergy syndrome, occurs when cross-reactions between pollen allergens and food allergens cause itchiness and swelling in the mouth and throat after eating the food allergen. Typically this is a mild reaction that is limited to the mouth and does not progress to systemic (anaphylactic) symptoms. Antihistamines are a good treatment for this.

Question: Are there links between food intolerances (e.g. lactose) and skin reactions such as psoriasis?

Answer: There are no links known at the present.

Question: Are those who suffer from MSG allergies more apt to have problems with seasonal allergies?

Answer: There is no relationship between seasonal allergy and MSG intolerance.

Question: What are common symptoms of food allergies?

Answer: Symptoms can vary, but common food allergy symptoms are abdominal pain, vomiting, diarrhea, trouble swallowing, swelling (of the face, hands, etc), hives and itching. Some children and adults also experience coughing and wheezing. In very severe cases, trouble breathing, fainting and shock can occur.

Question: What foods are most likely to cause food allergy?

Answer: The most common foods to cause allergic reactions in young children are milk, eggs, wheat, soy and peanuts. The most common foods to cause allergic reactions in adults are fish, shellfish, peanuts and tree nuts.

Question: What is the difference between food allergy and food intolerance?

Answer: Having an unpleasant reaction to food is a fairly common problem. Fortunately, true food allergy is a relatively uncommon medical problem. An allergic reaction to a food is caused by the immune system overreacting to a specific component of that food. A food intolerance can cause similar unpleasant reactions when eating a food, but the immune system is not involved. The most common example of a food intolerance is lactose intolerance.

Question: Can an antihistamine prevent allergic reactions for food allergies?

Answer: For those with true allergy to a food, taking an antihistamine during an allergic reaction may be helpful to relieve the hives and itching. They have little role in relieving any type of respiratory problem. If a child is having anaphylaxis or respiratory symptoms (e.g. throat closing, coughing, wheezing), the only treatment that is effective is injectable epinephrine (EpiPen or AuviQ). For adverse reactions to foods, which are not allergic in nature, antihistamines have little effectiveness.

Question:Can someone outgrow peanut allergy?

Answer: Young children often outgrow their food allergies, especially to soy, wheat, egg, and milk products. It is less likely that a child will outgrow peanut allergy. However, studies during the past few years have indicated that about 20 percent of children with allergic reactions to peanut in the first years of life may eventually outgrow their sensitivity. Children with food allergies should see their allerfist at least annually to reevaluate their allergies.

Question: My son's last test results are worse than ever. His allergen levels rose for both cashews and walnuts. Do you think this means he's getting exposure to these allergens, somehow?

Answer: It is difficult to give a definitive answer. This is not uncommon. It could be that different labs were used. It could be that he has had minor, even cutaneous (skin) contact or that his immune system is more mature and stimulation has led to higher levels. It could be that he has been exposed to cross-reacting allergens that have yet to be recognized. You should consult with your pediatric allergist.

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