There is evidence that allergic disorders such as asthma, eczema and hayfever - as well as food intolerances - are on the increase. It is estimated that one in four people will have an allergy during their lifetime and that half of those may be children, although allergic reactions can appear at any age.
Allergies are not nearly as common as people think. In one study, when researchers asked people if they reacted to foods, one in five said yes. However, only one in 50 had objectively reproducible symptoms. Despite this, the potential seriousness of allergic reactions should not be underestimated as, tragically, people can and do die as a result.
The immune system is supposed to protect the body from 'attack' by bacteria or other harmful substances. An allergic reaction happens when the immune system misinterprets harmless substances - such as food, latex or pollen - as a threat. True allergy is relatively rare, but is more likely to cause life-threatening symptoms; peanuts are probably the best known example. However, people may also have an intolerance to a substance; this refers to any reproducible adverse reaction, which is not psychologically based, but where there is no evidence that the immune system is involved.
Allergic reactions are caused by substances in the environment called allergens. Almost anything can be an allergen, but allergens usually contain protein, which is what triggers the reaction in the immune system. Conversely, other substances - such as the drug penicillin can also cause allergy.
Some people are more ‘allergic' than others; the scientific term is atopic. If you suffer from atopic conditions such as eczema, asthma or hayfever, your children are more likely to suffer, too. However, some children's allergies can just appear out of the blue.
Allergy can affect any system in the body including breathing, the skin or the gut. There are many different symptoms that could indicate that someone is suffering from an allergy. It has to be remembered, however, that many of these symptoms can be caused by other things; some, such as asthma and eczema, are conditions in their own right.
In general, it is easier to diagnose an allergy if the symptoms appear quickly; a rash after using latex gloves or breathing difficulties after a peanut butter sandwich. The most serious symptom of allergy is anaphylaxis or anaphylactic shock, which is a potentially life-threatening form of allergic reaction. The person may start to have severe difficulties breathing, have swelling particularly of the face or neck and may collapse. An ambulance needs to be called immediately. Anyone who knows that they have anaphylactic reactions will usually carry an adrenaline pen which needs to be injected as soon as possible by the person themself, or someone with them.
Quick Onset Slower Onset
Asthma/breathing difficulty Eczema
Swelling of lips, tongue, mouth, throat Failure to thrive (in children)
Vomiting Colic/stomach pains
Rash Diarrhoea
Sneezing/runny nose Constipation
Anaphylaxis Reflux (vomiting and/or pain)
Itchy eyes/ears/mouth Migraine
Urticaria (nettle rash/hives)
It has become very fashionable to blame everything on allergies. However, allergic reactions are on the increase, so it is wise to ensure that you are able to separate fact from fiction in this difficult area.
