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Last updated: 07.03.18

How to Recognise Symptoms of Food Allergies in Adults

Food allergies can range from being very mild to life threatening, and in many instances, people are unaware that they have an allergy, or indeed if they’re suffering from an allergic reaction. As a result, it’s useful to understand a little bit about the different types that can occur, and how you can recognise the symptoms. For those that experience very mild reactions, it can be useful to help diet management, but in serious allergies, knowing how to spot symptoms can help to save a person’s life. In the interests of food allergy awareness, let’s take a look.

Firstly, it’s important to note that there are two main types of allergies. There are what are called IgE-mediated food allergies, and non-IgE-mediated food allergies. The main difference between the two is that IgE-mediated food allergies will generally present symptoms within seconds or minutes of coming into contact with, or ingesting the food, whereas non-IgE-mediated food allergies tend to present symptoms over a longer period - up to days in some cases.

IgE-mediated Food Allergies

As already mentioned, IgE-mediated food allergies will present symptoms almost straight away, so if someone experiences any of the symptoms we’re about to look at, it’s very possible that they’re as a result of consuming a food they’re allergic to. It’s important to bear in mind that not all allergic reactions are equal - some people might experience the following in a very mild way, whereas for others medical attention may be required. Judgement has to be made on a case-by-case basis.

The main symptoms of IgE-mediated food allergies are the following:

  • A tingling or itching sensation in the mouth, often in the gums
  • Itchy and red rashes that can often be raised
  • General swelling, usually constrained to the face and lips or mouth
  • Swelling can also cause difficulty or discomfort when swallowing
  • Itchy eyes
  • Sneezing
  • Some breathing difficulties or shortness of breath
  • Dizziness and nausea
  • Diarrhoea and other abdominal pains

In some cases, IgE-mediated food allergies can be considerably more severe, resulting in anaphylaxis, which is also commonly known as anaphylactic shock. This is a medical emergency with potentially life threatening consequences. If you suspect that someone is suffering from this condition, then you must call 999 immediately.

Symptoms of anaphylaxis can include all of the above to a more severe degree, in addition to the following more severe presentations:

  • Loss of consciousness
  • Major breathing difficulties and wheezing
  • A very fast heart rate
  • Drop in blood pressure
  • Confusion
  • A feeling of fear or anxiety

Non IgE-Mediated Food Allergies

These types of allergies are often harder to identify, as they will present themselves well after ingestion of the food. Certain symptoms are similar to IgE-mediated food allergies such as rashes, and are easier to identify. However, non-IgE-mediated food allergies can cause any of the following symptoms, which are often thought to be the result of a different ailment given the difficulty in connecting them with the consumption of a type of food.

  • Heartburn and indigestion
  • Constipation or loosening of stool
  • Blood in the stool
  • Pale skin
  • Redness or rashes around the anus, rectum or genitals

Many of the above present themselves most frequently with children and babies. Colic for instance can be caused by allergies.

Finally, we should note that it is entirely possible for people to experience a mixed reaction, which is to say that after eating a food they are allergic to, they exhibit symptoms of both IgE-mediated food allergies and non-IgE food allergies.

Virtual College is pleased to offer a course on food allergies for those who wish to gain a better overview of symptoms and causes, along with what the law requires in order to reduce risks. Food allergy training may be especially useful for those employed in the catering industry. Click here to find out more about our food allergy awareness training course.