DR ISABEL SKYPALA is a consultant allergy dietitian and clinical lead for food allergy in the asthma and allergy group at Royal Brompton Hospital, London. She’s also an honorary clinical senior lecturer at Imperial College London
Compiled by Charlotte Haigh. Photographs: iStock, Getty
There’s a lot of confusion about allergy versus intolerance – and it’s not surprising. An allergy is when someone’s immune system makes immunoglobulin E (IgE) antibodies. These originally evolved to get rid of parasites but in Western societies nowadays, they wrongly identify something harmless – like pollen or a food – as a foreign body and get to work trying to move it out of the body. During an allergic reaction, the IgE links to the protein antigen (the immune response-provoking substance) in a food or pollen. The so-called mast cell that the antibodies sit on breaks open and releases chemicals called histamines, which lead to typical allergy symptoms – such as rashes, wheezing and/or a runny nose.
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