Food Allergy

Introduction

Food allergy is a common and serious health problem. It is estimated that 8% of children and 2% of adults suffer from food allergy in this country. An estimated 400 people die every year due to food allergy.

Types of adverse food reactions

There are three possible kinds of adverse reactions to foods. They are food poisoning, food intolerance, and food allergy. Food poisoning results from consuming uncooked or leftover foods contaminated with bacteria or their poisons. This results in the development of nausea, vomiting, diarrhea, fever, stomach cramps and even dehydration within several hours to 1-3 days after eating the contaminated food. This is usually a self-limiting condition and needs supportive treatment for recovery. Eating freshly cooked foods or eating foods that are correctly processed and preserved is the best way to avoid this problem.

Food intolerance is much more common than food allergy. Lactose intolerance is a good example of food intolerance. In this condition, the enzyme lactase in our small intestine that handles digesting lactose (sugar) in the milk or dairy products is missing or deficient. When lactase deficient persons consume milk or dairy products, they develop nausea, abdominal cramps, bloating, gas formation, and or diarrhea. dairyLimiting or avoiding milk and dairy products, using lactose-free milk or soy milk and using Lactaid tablets before eating dairy products are some of the methods of dealing with this problem.

What is a food allergy?

People with food allergies usually suffer from other allergic diseases such as hay fever, asthma, or eczema or have someone in the close family suffering from these problems. Food allergy usually develops during early childhood but can develop for the first time at any age.

The food allergic reactions consist of any combination of the following symptoms: Itching, hives, swelling of various parts of the body, diffuse redness affecting all over the body, cough, wheezing, difficulty breathing, tightness in the chest or throat, difficulty swallowing or talking, nausea, vomiting, abdominal pain, diarrhea, palpitations, dizziness, loss of consciousness and in rare situations even death. The Food allergic reactions typically take place in the first two hours after ingestion of the food. Alcohol and exercise following meals can speed up the process.

What are the relevant food allergens?

Eight foods- milk, eggs, soy, wheat, peanuts, tree nuts, fish and seafood (shellfish) account for 90% all food allergic reactions in children. Four foods- peanuts, tree nuts, fish and seafood (shellfish) cause 85% of all food allergic reactions in adults. Allergy to milk, eggs, wheat and soy are not permanent, and usually children outgrow them between the ages of 4 and 9. Allergy to peanuts, tree nuts, fish and seafood (shellfish) are life-long. About 20% of children with a peanut allergy outgrow it. Besides these conventional foods, foods such as onion, mustard, garlic, sesame seed, sunflower seed, coconut and fresh fruits and vegetables can also cause food allergic reactions in susceptible people. Food allergic reactions due to dyes, chemicals, and preservatives in foods are exceedingly rare. There is no approved skin or blood test to diagnose this problem. A carefully documented food diary may help us narrow down the culprit.

How do you diagnose food allergy?

Diagnosis of food allergy depends on two parameters: Carefully documented history compatible with food allergy and a positive skin test or blood test to the suspected food. Fifty percent of food allergy test results are false positive (Test is positive, but the patient lacks accurate history to support a diagnosis of food allergy). On the other hand, a negative food allergy test nearly (> 95%) rules out allergy to the food in question. Therefore, diagnosis of food allergy is not as simple as doing a skin test or blood test, and it needs the skill, training and interpretation of a qualified physician such as an allergist and immunologist.

How do I manage my food allergy?

The first and foremost step in dealing with food allergies involves education of the patient, family members, other caretakers and the public at large. It is crucial for people to realize that food allergic reactions are potentially dangerous and are preventable. People should be trained to read food labels and avoid the allergy causing foods. Making the house peanut and tree nut free is not unreasonable when you have a family member who is allergic to one of these foods. Utensils such as plates, glasses, spoons, forks, knives, etc. may accidentally contain trace amounts of the food to be avoided due to improper washing. When such utensils are used, food allergic reactions could ensue.

Eating outside and travel are two potential hazards for food allergic patients. Checking with a restaurant manager or chef is perhaps the best safeguard. If your child has food allergies, the school, daycare or other caretakers should be notified. It is important to educate your child not to share food with other children. It may even be better to send home-made food to school or daycare. Adult supervision is essential during lunchtime or snacktime at school, especially for small children. Wearing a medic alert bracelet is beneficial for all age groups. People with food allergies should carry with them two EpiPen injections for self-administration at all times for emergency use. Patients or responsible adults should be trained in the use of EpiPens. A written and well-understood food allergic action plan is necessary also in dealing with emergencies.

Is the development of food allergy preventable?

Development of food allergies in children can be minimized if not prevented by following this advice: It is best to avoid eating peanuts during pregnancy and lactation when there is a strong family history of allergies in general and food allergies in particular. It is also important to postpone the introduction of certain allergenic foods in the child's diet until much later. For example it is recommended that cow's milk be introduced after the age of one year, eggs are introduced after the age of 18 months and peanuts, tree nuts, fish and seafood are introduced after the age of 3 or 4. It is also recommended that breast-feeding should be carried out for at least one year. Solid foods in the child's diet should be delayed until after the age of 6 months. Experts also recommend a routine allergy evaluation and screening by a qualified allergist and immunologist at the age of one year in this field.

Where can I learn more about food allergies?

There are organizations such as food allergy anaphylaxis network (www.foodallergy.org), American Academy of Allergy, Asthma and Immunology (www.aaaai.org) and American College of Allergy Asthma and Immunology (www.acaai.org) which are devoted to educating the public. Visiting their websites is the best way of ensuring that you know all about food allergies.