When that tummy ache might be a food allergy

They are a testament to the increasing prevalence of allergies among young Thais. An allergic reaction is the body’s response to substances called allergens. These substances can be inhaled or swallowed. A child could be allergic to pollen, reacting to its presence in the atmosphere when he inadvertently breathes it in. Or he could be allergic to peanuts, which you might discover only after he’s eaten some. Food allergies can trigger symptoms related to the skin (rashes/hives), respiratory system (runny nose, wheezing), and the gastrointestinal tract (constipation, blood in stools).

Abdominal pain is a common complaint among children suffering an allergic reaction. Tummy pain that seems similar to acidity might indicate gastric acid secretion in response to food. Abdominal cramps and intestinal spasms could also occur as part of an allergic reaction to highly allergenic foods, such as mackerel. Some food allergens can cause ulcers, diarrhoea, vomiting, and vomiting with blood. There might be itching or tingling in the mouth and the lips, face or tongue, or the throat could swell up making it difficult to breathe. Other kids might feel lightheaded or dizzy. Sneezing or cough, runny or itchy eyes can also indicate an allergic reaction. A sometimes fatal allergic reaction is anaphylaxis, characterised by a drop in blood pressure, shortness of breath, a rapid pulse, and unconsciousness. It requires immediate medical attention.

An allergic reaction occurs when the body’s immune system interprets certain proteins as harmful foreign bodies. An antibody, immunoglobulin E (IgE), attacks these unfriendly proteins, and triggers the release of certain chemicals that cause various reactions such as breathlessness or nausea. 

Genetically speaking, a naturally high IgE level can make some children prone to allergies. But there are other body responses which are not IgE-related – the so-called Non-IgE mediated, which cause tummy pain, bloody vomiting, slimy stool or bloody stool.

Research indicates that children are more likely than adults to suffer from allergies, probably due to the immaturity or lack of development of the bowel. A child’s immune system reaches maturity after it turns two. If exposed to allergens before this age, children tend to become more sensitive to these substances. For instance, asthma can be controlled if diagnosed early (before 7 years of age) but if it persists beyond 7 years of age, it could last a lifetime. Most children outgrow food allergies by the age of 3. So, if you ensure that your children avoid the food they are allergic to for a few years and then reintroduce these foods into their diets gradually and in small amounts as they grow older, you might discover that they have outgrown their allergies. 

Food allergies and food intolerance cause similar symptoms: nausea, diarrhoea, vomiting, and abdominal pain. The difference is in the quantity consumed and the intensity of reaction. If your child is allergic to a particular food item, like milk, his body will react each time he eats or drinks the item, regardless of how much or how little. In contrast, food intolerance is related to the amount consumed. So, if the child shows a reaction after having 500ml of milk, but not after drinking 200ml, he probably suffers from food intolerance, which means complete avoidance of the food item may not be necessary, just judicious consumption.

Some foods are notorious for triggering allergies, the most common being shrimp, lobster, crab, prawns, peanuts, walnuts, some types of fish, eggs and cow’s milk. An allergic reaction is usually immediate. 

Since some symptoms of food allergies, such as abdominal pain, could be indicative of other problems as well, diagnosis can be tricky. Food allergy cannot be checked by a blood or skin test. A food challenge test is best. 

This involves having the child consume certain foods to test its reaction to these foods. The test is usually conducted in a hospital as an outpatient procedure and the child is monitored by medical personnel. If the child’s reaction is severe, she/he is immediately admitted for treatment. This test helps eliminate non-allergens and identify allergens. However, only one food item can be administered at a time to enable undisputed identification of allergens. 

Treatment for allergies is usually symptomatic. Some medicines may be given to relax the bowel and help it contract smoothly. Others help dilate the bronchi and ease breathing. Antihistamines block the histamines produced by the immune system in response to allergens. In some cases, inflammation caused by allergic reactions may be treated using steroids.

Some parents worry too much about potential allergens and restrict their children’s diets. As a result, children might be malnourished or suffer calcium or vitamin deficiencies. They could also develop food phobias. It is better to neutralise allergens by strengthening the intestine. This can be achieved by adding good bacteria (probiotics), good fibre (prebiotics), and unfermented food to the diet. Certain foods, like cow’s milk, could be replaced with medicated milk. Over time, children could be weaned off the medicated option in favour of the regular one. That tummy ache will then be a thing of the past.

 

PROFESSOR BOOSBA VIVATVAKIN is a Paediatric Gastroenterology and Hepatology specialist at Samitivej International Children’s Hospital. |Call (02) 711 8236-7.