What is an allergic reaction?
Your body has a system designed to protect it from outside harm, called your immune system. The immune system works by identifying harmful substances such as germs, or poisons, and produces antibodies: specialist proteins that help white blood cells to ‘fight’ the harmful substance. However, sometimes your body can mistakenly identify a harmless substance, such as pollen, as a threat. It produces antibodies to try to fight off the threat, and it is these antibodies that produce side effects. Depending on the allergen, the side effects will differ. If the body is releasing the antibody histamine, side effects will include sneezing, swollen eyes and a runny nose. For skin allergies, symptoms include redness and dryness, or a rash.
Causes of allergic reaction
Although it is possible to have an allergic reaction to almost any substance, there are a few common allergies that many people suffer from. Dust mites are a big cause of allergic reaction. Dust mites live in house dust, often in bedding or soft furnishings, and it is their waste that the body reacts to. For this reason, it is advised to change pillows and bedding regularly to prevent build-up of this allergen. Pollen is another very common allergen, so common in fact that we see pollen count recorded in many weather reports. As the temperatures rise, more pollen is found in the air, especially in less urban areas. Tree pollen is especially problematic as it is high in the air, meaning that as it falls it irritates those who are susceptible to it. Less common causes of allergic reaction include some prescription drugs or painkillers. Some people are allergic to antibiotics, and do not find out until they take the medication.
Symptoms and reactions
Symptoms of allergic reaction differ hugely. Some people only ever experience very mild symptoms – for example, sneezing when the pollen count is very high. Anaphylactic shock is the most severe reaction to an allergy and is rapid in onset. If untreated it can cause death, so it is very important that those with allergic reactions seek medical guidance in case they are in danger of reacting this severely.
Why does this happen?
It is not clearly understood why the body reacts in this way to certain harmless substances. There is a strong argument that genetics plays a part, as allergies often run in the family, and those born into families where parents suffer from allergies are more likely to suffer themselves. Although only one in five children are likely to develop an allergy in the UK, this risk is doubled if one or both of their parents suffer from an allergy themselves.
The hygiene hypothesis may also explain why allergies are increasing at a higher rate now than ever previously recorded. This hypothesis is the belief that the immune system needs to come into contact with a wide range of substances whilst still in its infancy, but that due to modern hygiene practice, young children are no longer exposed to allergens. Infrequent exposure to micro-organisms may lead to the immune system developing a tendency towards allergy.
There is also evidence to suggest that an allergy can develop later in life as a result of stress on the body. This could be due to an unrelated illness or a major life event, for example bereavement.