When you have a food allergy you are allergic to some type of food or drink. Some of the most common food allergies are cow’s milk, nuts and eggs.
The allergy leads to different symptoms of varying severity, and often it depends on which food you are allergic to. In most cases, complaints caused by food allergies disappear when you avoid foods that you are allergic to. Sometimes you may need to learn more about foods to get a proper diet or avoid serious allergic reactions.
Food allergies are quite uncommon and usually make their debut when you are a child. It is unusual to have them as an adult. Allergy to cow’s milk and eggs is especially common in young children and usually disappears over time, while nut allergy and peanut allergy usually remain throughout their lives.
Food allergies are often confused with hypersensitivity (intolerance), such as gluten intolerance (celiac disease) and lactose intolerance. Intolerance has an unusually high sensitivity to certain substances. When you are allergic, an allergic reaction is triggered in the body, where the immune system’s antibodies start to defend themselves. Then the substance is produced histamine which leads to allergic symptoms. There are quite a few who suffer from different types of intolerance to food. However, food allergy is more uncommon.
Causes of food allergy
The causes of food allergy are complicated. What has so far succeeded in finding is that food allergies are most common in those with a tendency to have allergies. Many people with food allergies also have flexural eczema (atopic eczema). Environmental factors can affect allergies. Unfortunately, food allergies cannot be prevented.
The immune system usually responds to the proteins contained in the food. For most people with food allergies, it is necessary to chew, swallow or otherwise come into contact with the food to trigger a reaction. However, those with severe allergies may get reactions from inhaling what they are allergic to. It is for this reason that peanuts are no longer served on aircraft. Peanut allergy is an allergy that is linked to severe allergic reactions, called anaphylaxis.
Symptoms of food allergy
The most common symptom of food allergy is mouth problems such as itching of the palate, throat and lips. It usually arrives within 15 minutes and disappears quickly. These reactions can often be linked to so-called cross allergy, in which you react to allergies from a source similar to another that you are allergic to. Cross allergy is often linked to pollen allergy.
Signs of food allergy may appear in the mouth, on the skin and in the stomach. In rare cases, respiratory symptoms can occur, and those with very severe allergies may have allergic reactions (so-called anaphylaxis). Anaphylaxis occurs mainly in the case of allergies to nuts and peanuts.
Some typical symptoms of food allergy are:
- Mouth symptoms such as irritation, itching and swelling
- Skin symptoms such as eczema, hives and redness
- Stomach symptoms such as vomiting, diarrhea, stomach pain and constipation
If respiratory symptoms occur, it is usually in the form of sniff, nasal congestion, allergic asthma. In case of severe allergy, severe allergic reactions may occur.
Investigation and diagnosis
In case of suspected food allergy an investigation is made. For example, it may consist of:
- Questions and forms about reactions to different foods
- Skin testing, eg different types of so-called dot tests where you see if you react to different substances
- Removing certain foods from the diet
- Food provocation, where suspected allergy-causing food is put into the diet to see if you are reacting (if there is no risk of serious reactions)
- Symptom registration in diary
Children under the age of six often need to come back for regular examinations because their food allergies usually disappear over time. For example, egg allergies and milk allergies often disappear over time, and then the child can start eating foods containing substances that have previously been allergic to.
Treatment of food allergy
There is no treatment that cures food allergy. In most cases, it is enough to stop eating the one you are allergic to. Sometimes you may need to contact a dietician or so-called food school to learn what you cannot eat. It can also be a good way to get a balanced, nutritious diet in spite of not eating certain foods. If you have an allergic child, the preschool or school needs to be clearly informed about what the child cannot eat. It can also be good to inform about what needs to be done in various allergic reactions so that there is no misunderstanding. You need to be careful to look at table of contents yourself, as traces of eg eggs and milk can be found in many semi-finished products.
Prescription-free medicines for allergies can help in relieving symptoms. There are also various allergy medicines that are prescribed by prescription if the doctor thinks it is necessary. In the case of severe allergies, an adrenaline pen or cortisone tablets may be needed to stop allergic reactions.
When should you seek care?
Seek care at a health care center:
- In case of suspected food allergy
- If you exclude food you are allergic to and still get symptoms
- In case of allergic reactions to food
Seek emergency care at:
- Increasing swelling in the throat
- Severe itching