Food allergy is an immune system reaction occurring from eating some foods. Most times, small amounts of the allergy-causing food can result in an allergic reaction with symptoms such as swollen airways, hives or digestive problems. In certain cases, a food allergy may lead to severe symptoms or a life-threatening reaction called anaphylaxis.
Research shows that food allergy affects about 8% of children below five years and 4% of adults. Although food allergy has no cure, some children outgrow it. Many people mistake a food allergy with a more common reaction called food intolerance. Food intolerance is discomforting but less serious than a food allergy and doesn't involve the immune system.
Some people experience an allergic reaction to a particular food. This may be uncomfortable but not severe. In other people, the allergic reaction can be severe and life-threatening. Symptoms of a food allergy often occur within a few minutes to two hours after eating the allergy-causing food. In a few cases, the symptoms are delayed for a few hours.
Common signs and symptoms of food allergy include:
Sometimes, food allergy can trigger a more severe, life-threatening reaction called anaphylaxis. The signs and symptoms may include:
The following tests can help diagnose food allergies.
The skin prick test is a sensitive food allergy testing method that gives a fast result, usually within 30 minutes of testing. In this test, the healthcare professional will prick the front or back of the arm's skin using a sterile probe, then induce a small amount of the suspected allergy-causing food. While this test doesn't cause pain, it is usually uncomfortable.
The test result is positive if an allergic patch develops on the skin. If an allergic patch isn't present, the test is negative. However, the test doesn't determine the level of allergy.
This blood test is another effective option to diagnose a food allergy. The diagnosis depends on the total number of allergic antibodies present in the blood.
Although the oral food challenge is an effective test, it is expensive. It aids diagnosis of any allergy. The oral food challenge involves eating increasing amounts of the allergic food but under clinical supervision to determine the presence of an allergy and its effect.
Other food allergy testing options are:
You can prevent food allergy by avoiding the foods that cause your signs and symptoms. Regardless of how hard you try to avoid food allergens,you may still take foods that cause a reaction.
You may take prescribed or over-the-counter antihistamines for minor food allergic reactions to alleviate the symptoms. You can take these drugs following exposure to an allergy-causing food to relieve hives or itching, but antihistamines cannot treat a severe allergic reaction.
An emergency epinephrine injection or a visit to the emergency room may be necessary when you have a severe allergic reaction. Many people experiencing severe food allergies carry an epinephrine autoinjector (EpiPen, Adrenaclick). This device has a syringe and concealed needle that injects a dose of the medication when pressed against the thigh.
If your doctor prescribes an epinephrine autoinjector
Research is ongoing to find better treatments that reduce food allergy symptoms and prevent allergies, but there is no proven treatment to relieve or prevent symptoms completely.
A treatment currently studied for food allergy is oral immunotherapy. This treatment involves swallowing or placing small doses of the allergy-causing food under the tongue, then gradually increasing the doses.
One oral immunotherapy drug has been approved to treat children between 4 – 17 years with confirmed peanut allergy, but this medication is unsuitable for those with uncontrolled asthma or other conditions, including eosinophilic oesophagitis.
One way to avoid an allergic reaction is to avoid the food that triggers your symptoms.
Ensure you read all food labels to ensure they contain no allergy-causing ingredients. Even when you know what the food contains, check the label, as the ingredients may change. Food labels must clearly list if the food product has common food allergens.
Read the food labels carefully to avoid the most common sources of food allergens such as peanuts, fish, soy, wheat, eggs, milk and shellfish,
You are always at risk of eating food you are allergic to at social gatherings and restaurants. Many people do not realise the severity of food reactions and how only a small amount of food can cause severe allergies in some people. If you think a food may contain something that may trigger your allergy, do not eat it.
If your child has a food allergy, inform your relatives, teachers, babysitters and other caregivers. Ensure they understand the importance of your child avoiding foods that cause allergies and what they should do if an emergency occurs.
Informing the caregivers of the steps to take to prevent a reaction is also important such as carefully washing hands and cleaning surfaces that come in contact with any allergy-causing food,
A food allergy may cause concern, affecting work, home and school life. It may also make daily activities that are easy for most families, such as meal preparation and grocery shopping, stressful for peoplewith food allergies.
The following strategies can help manage stress resulting from food allergies.
Discussing your food allergies and exchanging information with people that have the same concerns may be helpful. Many non-profit organisations and internet sites provide information and platforms for discussing food allergies and issues resulting from it. Some are mainly for the parents of children who have food allergies.
Ensure family members and caregivers understand your child's food allergy, including school staff and babysitters.
Some children get bullied at school because of their food allergies. You should discuss your child's allergy with school personnel to reduce your child's risk of being a target of bullying.
Doctor's appointments are usually short, and there are usually many things to discuss, so it's important to prepare for your appointment. The information below can help you prepare for the appointment and know what to expect.
Preparing a list of questions beforehand will help you make the most of your little time with the doctor. You should consider listing the questions from the most important in case you run out of time.
Some questions you can ask the doctor are:
If the visit concerns a child with a food allergy, you may also ask the following questions.
Your doctor will likely ask several questions. Preparing to answer these questions will help save time during the appointment. These questions include:
Ensure you see an allergist or healthcare provider if you experience food allergy symptoms shortly after you eat. If possible, visit the healthcare provider during the allergic reaction to help the provider make an accurate diagnosis.
Emergency care is necessary if you develop symptoms or signs of anaphylaxis, such as:
Can my GP conduct a food allergy test?
If you think you have an allergy reaction, visit your GP. If,after discussing your symptoms, your GP thinks you have an allergy, you may need a blood test called RAST test to determine the cause of your allergy. The GP may also refer you for further testing to identify the cause of your allergy.
How do you test for a food allergy in the UK?
You may need a blood test called a specific IgE test that measures the amount of IgE antibodies if the doctor suspects food in the blood. This test is a Radio Allergo Sorbent Test (RAST). Your result will help diagnoseIgE-mediated food allergy, including a detailed clinical history. Your hospital clinician or GP will conduct the test.
Which food tolerance test is most suitable?
Several food intolerance tests are available, but the most accurate food intolerance tests include the blood test for testing gluten intolerance and coeliac disease and the hydrogen breath test for diagnosing lactose intolerance.