What do I need to know about food allergies?
Food allergies occur when the body’s IgE antibodies react to food proteins. The IgE antibody identifies this food protein as an invader hence causing mast cells (cells that are located throughout our body like skin, digestive system, esophagus, lungs, nose) to release histamines. Histamines cause a range of symptoms like itching, hives, coughing, sneezing, wheezing, diarrheoa, swelling of lips/throat and vomiting. Reactions can occur within seconds to up to 2 hours.
Although rare, this response can escalate to become anaphylaxis — a severe reaction that may cause airway constriction, extreme blood pressure drop and death. There is no cure for food allergies at this time.
Intolerance and Coeliac disease are not food allergies
Lactose intolerance is not a food allergy but a condition caused by a deficient enzyme that breaks down lactose (a sugar) found in dairy products. Coeliac disease is not a food allergy as it is a lifelong autoimmune reaction that attacks its own tissues in the digestive system; wheat, barley, rye and oats are all glutens that are to be avoided by coeliac individuals.
How are food allergies diagnosed?
At this time there are only two tests that can help diagnose food allergies: Skin Prick Test (SPT) and the blood test known as ImmunoCapRast or more commonly known as RAST. Both of these tests are available in International Medical Clinic and should only be done under supervision of a general practitioner or certified allergist.
The results of the diagnostic tests will not predict the severity of a reaction; rather the results will predict if a reaction will occur. The best diagnostic tool for allergists is the patient’s history. If a visit to an allergist is planned, provide the allergist with a food diary and corresponding reactions if possible. If a food allergy is still in question after testing, the physician may perform an In-Office Food Challenge (without a history of anaphylaxis) to truly confirm a food allergy. An Epipen® can only be dispensed with a doctor’s prescription. The IgG test is not accepted for food allergy testing.
What is the treatment for food allergies?
The only treatment for food allergies is to prevent any reaction by strict avoidance of food allergens. To treat a reaction that is severe, an injection of Epinephrine (Adrenaline) using an auto-injector called an Epipen® can prevent death by stopping the anaphylaxis and thus reducing the symptoms. Concurrent food allergy and asthma increases the severity of a food allergic reaction. Timely treatment of a reaction is crucial.
Based on statistics here in Singapore as well as the US, Australia and UK, food allergies are the leading cause of anaphylaxis. Top food allergens, based on US, Australia and UK research include: milk, egg, wheat, soy, peanut, tree nuts, seafood, crustaceans (shellfish such as prawns), and sesame (with mustard and celery added to the UK list). According to statistics from these countries, 6-8% of children under 3 years old have food allergies. Those with milk, egg and soy allergies will mostly outgrow their allergies by age 10; those with peanut, tree nut, seafood and crustacean allergies may expect lifelong reactions.
What happens after food allergies are diagnosed?
Once a child is diagnosed with a food allergy, the family will undergo major lifestyle changes. According to a study, families with a food allergic child deal with more stress than those with epileptic or asthmatic children. A normal lifestyle can be achieved by following simple guides:
- Avoid food allergens: No amount, not even a trace amount, is acceptable.
- Read labels: Take time in the grocery store to read the ingredient list. Learn alternative names for the allergen. For example, peanut oil is also known as arachis oil and can be found in sauces and salad dressings. Avoid bakery items as cross-contamination is high. If in doubt, do not consume anything without reading an ingredient label. Never assume.
- Practice the emergency plan: Create a plan to know when to administer antihistamine or an Epipen© with your doctor. Have all family members know their role during an emergency — including the help at home. Know which hospital is closest, both at home and school. Update this information regularly.
- Teamwork: School teachers, nurses, caregivers and the child — everyone has their responsibilities. Make sure a school policy is in place and the emergency plan can be followed at school. Empower your child with knowledge and make sure they understand the rules of not sharing food nor eating anything offered. Class/school training on food allergy awareness is essential. Everyone should know what to do in case an accidental ingestion occurs. Communicate with family, friends and school.
- Join a support group: Learn to cope, to share and understand more about food allergies through other families dealing with the same everyday issues (www.foodallergysingapore.org).
Most local and international schools can support children with food allergies.
Currently major research is underway to find a cure. Perhaps as soon as two to five years from now, a cure will be available where anti-IgE therapy will be able to shut down the whole allergy system for food allergies.