What is food allergy? What is the difference between food allergies and intolerance?
There are a lot of definitions about food allergies. In simple term food allergy means that the immune system overreacts to certain proteins or allergens in food.
Who are the people who need to know most about food allergies?
- Children with food allergy and their caregivers
- Healthcare providers
- Food service staff and managers from settings at risk for allergic reactions to foods
- Early childhood
- School principals, teachers, school staff and volunteers
What are the symptoms of food allergy?
- Urticaria and angiodema
- Swelling of the airway, low blood pressure
- Anaphylactic shock
In chronic conditions a chronic allergic inflammation of the esophagus known as eosinophilic esophagitis, with symptoms of food impaction, vomiting, and heartburn.
What are the other symptoms similar to allergy?
- Lactose and gluten intolerance
- Attention deficit hyperactivity disorder ADHD in children
- Energy drinks and colas
- Some fruits like bananas contain substances which can cause a reaction similar to allergy.
What is the difference between allergy and intolerance?What is gluten and lactose intolerance?
In intolerance the body does not have the enzymes to digest certain foods.
In lactose intolerance the body lacks the enzyme lactase which digests lactose, or milk sugar. Such patients cannot consume milk or dairy products like cheese, yoghurt,etc
Symptoms of lactose intolerance are:
- Bloating of the stomach
- Stomach cramps
- Rumbling of stomach
- Feeling sick
In this case major dietary changes will help. Milk and milk products have to be eliminated from the diet.
In addition to dietary changes, you may also find it useful to take liquid drops, tablets or capsules that contain lactase substitutes. These are available from most health foods shops.
Lactase substitutes replace the lactase your small intestine isn’t producing, which can reduce your symptoms by helping your body break down any lactose in your diet more easily.
Lactase substitutes can either be added to milk or taken just before eating a meal containing lactose.
Gluten intolerance or Celiac disease
This is an autoimmune disorder where your immune system reacts abnormally to gluten
If you eat eat food containing gluten like wheat, barley and rye, your immune system will act on the lining of your digestive organs like stomach and intestines, destroying the delicate highly absorbent cells. This can lead to long term complications like malnutrition and permanent damage to the stomach lining.
- Gas, abdominal bloating
- Pale, foul smelling stool
- Vomiting, diarrhea
- Stomach pain
Gluten intolerance can affect growth and development. It can cause emotional disorders too.
The treatment is avoiding food that contains gluten.
What are the common foods that cause allergies?
The eight common foods which cause allergies are:
- Tree nuts
Identifying food allergies is extremely important because a single whiff or contact can cause a severe life threatening reaction called anaphylaxis.
What is anaphylaxis?
It is a severe shock reaction which happens in food allergies. The symptoms are:
- Sudden drop of blood pressure with increase in heart rate
- Swelling of lips and wind pipe
- Cardiac arrest
- Nausea, vomiting
- Feeling of anxiety or as if something is “not right”
- Rashes, angioedema, hives.
The immediate treatment is injection of adrenaline deep intramuscular in the upper and outer part of the thigh. In western countries epi-pen auto-injectors are available which patients have to carry all times. Dose is advised
Sometime the patient has to be intubated or a tracheostomy( an opening in the neck where a tube is placed so that the patient can breathe directly)has to be performed in emergency to improve breathing.
Treatment of food allergies
Primary the food allergies have to be identified. Your doctor will ask you a lot of questions,
Allergy skin prick testing is done to identify the exact food causing allergies.
Avoidance is the primary treatment of food allergy. Proper identification of food allergies and reading of labels of processed foods available in the market should be done.
Some patients get a severe anaphylactic reaction to the smell of seafood or peanuts.
How to prevent food allergies?
- To prevent allergies in infants solid foods should not be introduced early.
- The hygiene hypothesis comes to play, that if small children are allowed to play in nature and with pets have fewer chances of developing allergies when they grow older
- Children can outgrow allergies to milk, egg, soy and wheat.
- Seafood and peanut allergies can persist through life.
- Food allergies in adults may last lifelong.
Immunotherapy for food allergy
Subcutaneous immunotherapy for food allergies is highly risky due to the extreme high risk for anaphylaxis involved
Oral immunotherapy (OIT) for food allergy
- Oral immunotherapy (OIT) is a potential treatment for food allergy (also known as desensitisation) that involves administering gradually increasing amounts of food allergen under medical supervision.
- It is important that patients and their families are aware that OIT methods are not currently standardised or approved for routine treatment of food allergy globally. There are concerns about a high (or unknown) risk of potential harm in patients with severe food allergy, as well as considerable cost implications.
- There have been recent social media reports about the use of OIT as a potential treatment for food allergy, particularly in the USA. However, currently there are no OIT methods approved by the Food and Drug Administration (FDA) to treat food allergy in the USA. These methods are still under development and until these are approved, experts do not recommend OIT for use outside of clinical trials.
- Currently there are several clinical trials on OIT for food allergy underway in Australia and other countries. The trials aim to develop standardised and proven methods to maximise benefit and reduce the risk of potential harm in patients with severe food allergy. These trials are all hospital based due to high rates of allergic reactions, including anaphylaxis, and other adverse reactions. Until these trials are completed, with methods, safety and effectiveness determined, ASCIA recommends that OIT for food allergy should not be performed outside of clinical trials.
- The possible benefits from OIT are desensitisation and tolerance. Published trials show that OIT for food allergy can result in desensitisation in many patients. This is a temporary state of protection that allows an increased amount of food allergen to be eaten without having an allergic reaction. However, it requires regular eating of the food and may still result in allergic reactions, including anaphylaxis, and other adverse reactions.
- Published trials have shown a limited ability for OIT to result in ongoing tolerance and permanent benefit. Tolerance is the ability to eat a food allergen without allergic reactions, that continues after OIT is stopped and does not require regular eating of the food.
- Until OIT for food allergy is proven and standardised for routine use, and shown to be safe to undertake at home, avoidance of confirmed food allergens is essential for the management of food allergy.
The same facts as above apply for sublingual immunotherapy
The above article is for information purpose only. Please contact your doctor for expert management