Food Allergies

A food allergy develops when the immune system attacks a normally harmless substance and creates antibodies.

  • What is it
  • Who is at risk
  • Outgrowing
  • Food allergens
  • Symptoms
  • Diagnosis
  • Treatment
  • Cross Contamination
  • Food Intolerance
  • Lactose Intolerance
  • Celiac Disease
  • Eosinophilic Esophagitis

Food Allergies

What is it

As with any allergy, a food allergy develops when the immune system attacks a normally harmless substance and creates specific antibodies for this substance. From this point on, whenever the food allergy sufferer eats the food to which they’re allergic, the antibodies respond by releasing chemical mediators, like histamine, which cause allergic symptoms to appear.

Food Allergies

Who is at risk

Approximately 12 million Americans suffer from food allergies. According to the Asthma and Allergy Foundation of America, three to eight percent of children will have an adverse reaction to food at some point; and one to two percent of children have true food allergies. Those at risk include people who have a family history of allergies and people who have other kinds of allergies, including asthma. Asthma sufferers are at higher risk for experiencing a life-threatening allergic reaction to food.

Food Allergies


Many children outgrow food allergies by age four; however, allergies to peanuts, tree nuts, and shellfish usually last a lifetime.

Food Allergies

Food allergens

Eight foods account for over 90% of food allergies. These include:

  1. Cow’s Milk
  2. Eggs
  3. Peanuts
  4. Wheat
  5. Soy
  6. Fish
  7. Shellfish
  8. Tree Nuts

In addition to the most common foods listed above, any food can cause an allergic or adverse reaction to anyone at any time. Other more commonly reported food allergens include apples, apricots, asparagus, avocados, berries, buckwheat, carrots, chicken, cinnamon, citrus fruits, coconut, corn, dates, grapes, honey, lamb, lettuce, mustard, oats, peaches, pears, peas, pork, raisins, rice, rye, safflower oil, strawberries, sweet potatoes, tomatoes, turkey, veal, and yeast. Many people are also intolerant of or allergic to food dyes, additives, and preservatives in processed foods.

Food Allergies


Signs and symptoms of food allergy range from very mild to extreme and may include: a tingling of the mouth; fatigue; hyperactivity; anxiety; headaches; crying; sore muscles and joints; sneezing; runny nose; stuffy nose; urticaria (hives); eczema (skin rash); itchy skin; recurrent ear infections; congestion; abdominal pain; vomiting; constipation; diarrhea; swelling of the hands, feet, eyelids, tongue and lips; dark circles under the eyes; bronchitis; difficulty breathing; asthma; a drop in blood pressure; loss of consciousness; and death. Symptoms normally appear within a few minutes to a couple of hours after ingesting the allergenic food, but in some cases they may not appear until days later.

Food Allergies


Many people figure out the food to which they’re allergic by systematically eliminating suspected foods from their diet; this is known as an elimination diet. A skin test is often helpful in uncovering hidden food allergies, and while false positives are common, a negative skin test is a good indicator that one is not allergic to the food in question. A blood test, or a Radio-Allergo-Sorbent Test (RAST), measures the number of antibodies in the bloodstream. A positive RAST test is a reliable sign of an allergy; however, all allergies may not be detected. The best indicator of a food allergy is the observation of an allergic reaction. Sometimes doctors will give patients a small amount of a suspected allergenic food to see if an allergic reaction occurs; this is known as an oral food challenge. Oral food challenges can be dangerous and should never be attempted outside of a doctor’s care.

Food Allergies


Currently, there is no cure for food allergy. Strict avoidance of the allergenic food is the only way to prevent allergic reactions. Always check labels, ask about ingredients, and watch out for cross-contamination. Always carry your EpiPen in case of accidental exposure; it may save your life. If your child has a food allergy, make sure all teachers and caregivers know about the food allergy. Visual indicators such as clearly marked lunchboxes and food allergy t-shirts let people know about the child’s food allergy; such visual indicators are particularly valuable in situations like summer camp, where all adult supervisors may not know about the food allergy. Eating out in restaurants is risky; always carry Food Allergy Restaurant Cards to be safe. If you have a small child with a food allergy, use Table Toppers on public tables to avoid accidental exposure. You never know what’s on the surface of a restaurant table. People who are extremely allergic should always wear a medic alert bracelet.

Make sure you read labels in order to avoid foods or preservatives that cause a reaction. At the first sign of an allergic reaction to a food, call 911 immediately. Time is of the essence. Most food allergy fatalities occur within one hour of ingesting the allergenic food. If you are not minutes away from an emergency room, you may need to use an EpiPen, which you should always carry in case of an emergency.

Food Allergies

Cross Contamination

Cross-contamination occurs when an allergenic food touches another food or surface, such as a utensil, grill, countertop, table, plate, or someone’s hand. Cross-contamination is the primary vehicle of accidental exposure to food allergens. To avoid cross-contamination, pay close attention to food preparation, storage, and serving methods.

Food Allergies

Food Intolerance

Food intolerance occurs when your digestive system cannot handle a certain type of food, normally due to a missing enzyme. An intolerance may present some of the same gastrointestinal symptoms as a food allergy, such as abdominal pain and diarrhea. A food allergy, however, involves an allergic response from the body’s immune system.

Food Allergies

Lactose Intolerance

Lactose intolerance occurs when a person lacks the enzyme lactase, which is needed to properly digest lactose, a sugar found in milk and dairy products. A food allergy to milk, on the other hand, involves an allergic reaction to dairy proteins like casein.

Food Allergies

Celiac Disease

Also known as coeliac, nontropical sprue, celiac sprue, gluten intolerant enteropathy, or gluten sensitive enteropathy, celiac disease is the most common genetic disease in Europe. While similar to wheat allergy, celiac disease is actually an intolerance to gluten rather than an allergy. Gluten is a protein in wheat; it’s also found in rye, barley, oats, other grains, and many processed foods. When people who have celiac disease ingest gluten, it causes their immune system to attack the delicate lining of the bowel.  This can lead to bloating, cramping, gas, diarrhea, constipation, skin rashes, chronic fatigue, and even malnutrition (since the lining is responsible for absorbing nutrients).

Food Allergies

Eosinophilic Esophagitis

Eosinophilic esophagitis is an inflammatory allergic reaction of the esophagus, the tube that goes from the mouth to the stomach. “Eosinophilic” refers to eosinophils, types of white blood cells that increase in number during inflammation. Eosinophilic esophagitis commonly occurs among those allergic to cow’s milk, soy, eggs, and wheat, and it’s often accompanied by other symptoms of an allergic reaction.

Indoor Allergies
Eye Allergies
Food Allergies
Children’s Allergies
Drug Allergies
Outdoor Allergies
Skin Allergies
General Allergies

“My son has been going to Dr. Mery for over a year.  I always appreciate how attentive the nurses are to him when checking him out before he is released after his shot.  This office is very clean and organized as well.”

Stephanie H.

“My whole family goes to Dr. Mery.  He has been a major factor in our family’s health and well-being.  Dr. Mery is compassionate and understanding.  He is determined to help those who come to see him and truly cares for his patients.”

Susan D.

“Hill Country Allergy has been a very good experience for me these last few weeks. A great team has been providing me with a thorough job of evaluating my allergy needs and implementing a specific plan to reach my specific goal of setting my allergies under control. All staff is efficient, courteous, and very knowledgeable of my specific concerns. I am very pleased with my current service.”

Sandra B.

“The staff at Hill Country Allergy & Asthma is nothing short of amazing. They greet you with a smile and they actually remember my name; you are not just another face. They are patient and take the time to explain things even if you ask them the same questions every other time you are there. The technicians providing the shots are extremely careful and service is usually quick due to the check in system they utilize. They are well organized, with excellent customer service.”

Ditrell B.

“Whenever Julie is the one who gives me my shot, I almost look forward to getting the shot. Her sunny disposition brightens my day. I did say that it almost makes me want to get a shot!”

Bob B.

“I have been very pleased with the great care I have received from Dr. Mery, as well as his entire staff. They are all great!”

Cindy M.

“I look forward to getting my allergy shots every month. The office staff is so friendly and professional. It is a very nice and relaxed atmosphere too.”

Maria B.

“Dr. Mery saved me! I struggled for months with a skin reaction that three other doctors were unable to get under control.  It was clear from the onset that Dr. Mery is truly invested in his patients as he spent so much time with me trying to understand my situation and helped me tremendously with my condition.  Dr. Mery and his staff genuinely care for their patients!”

Krista H.

“My son saw Dr. Mery years ago for his bad allergies.  He was tested, started shots and has been on shots for a couple of years now.  We cannot begin to express our gratitude to HCAA for helping our family.  Our son is completely different kid – he can now play on sports teams and enjoy playing outside with his buddies!  THANK YOU DR. MERY!”

Sandy H.