IgE food allergy

A Type I immediate IgE hypersensitivity immune response is more commonly known as a food allergy and this reaction typically occurs very quickly (within minutes to hours) after eating an offending food, with symptoms ranging from mild to severe.

The mechanism which takes place in an IgE allergic reaction is initiated by these specific antibodies, by the activation of mast cells that line the body surfaces. Once activated, they  initiate the allergic cascade, stimulating inflammatory reactions by secreting chemical mediators such as histamine and cytokines.

Many are aware of food allergies causing anaphylaxis (the most common example being peanuts), but they may also experience itchy lips/tongue/throat, stuffy nose, headaches, stomach pain, diarrhoea, gas, bloating, skin reactions, and sudden fatigue.

Most people often know their ‘trigger foods’ because when the reaction occurs, it is so quick and happens soon after eating food. However, sometimes it isn’t always obvious, particularly with people who have multiple allergies. In these instances testing can be very useful and is done by measuring specific IgE antibodies in the blood to the suspected foods and food panels.

NB. IgE allergy is not something that we currently test for and will not be identified by our IgG mediated food intolerance tests. If an individual suspects that they may have an IgE allergy, then they should consult their GP to be tested for this.