The number of people affecting by allergies is growing faster than ever. What are the causes, the triggers and the remedies for those itching eyes and noses?
Summer is well and truly upon us and while this brings sunshine, barbecues and ice cream in the park, to millions around the UK suffering with allergies it’s the most challenging time of the year. Allergies affect about one in three people at some stage in their lives – and the number has risen sharply over the last 20 years.
Recent research confirms a significant increase in the incidence of allergies, including food allergies, in the UK. It is estimated that as many as 50 per cent of children are diagnosed with an allergic condition at some point in their childhood. We asked Dr Jonathon North at BMI Edgbaston Hospital, Birmingham to shed light on the reasons why allergies are becoming more common, how and when to get an assessment for diagnosis, and the treatments available.
What is an allergy?
“An allergic reaction occurs when your immune system responds to something that to most would be a harmless substance,” said Dr North. “Many people are allergic to pollens and house dust mite and there are various common food allergies to things like peanuts and eggs. However, almost anything can be an allergen.”
For most people these materials cause no problem at all but in those who are allergenic, their immune system identifies the substance as a ‘threat’ and subsequently produces an inappropriate reaction. When someone comes into contact with an allergen the immune system triggers an antibody response and releases a substance called histamine. Histamine is the chemical that causes the irritating, uncomfortable symptoms associated with allergies – such as sneezing, itchy eyes, and swelling.
Why are they getting more common?
“There is a widely-held belief that people are more likely to suffer from allergies if they have been exposed to fewer germs in childhood,” said Dr North. “This is known as ‘the hygiene hypothesis’ and while it has been talked about a lot recently, it is inaccurate and continues to mislead people to think that modern hygiene standards are bad for our health.”
Main allergy causes include:
- Genetics: A child born into a family where parents/siblings suffer from allergies has a higher chance of developing an allergy themselves.
- Environment: Current research shows that the allergy genes may be ‘switched on’ or ‘switched off’ by external environmental factors, such as viral infections.
- Antibiotics: Using antibiotics reduces the diversity and frequency of the bacteria on your skin and in your gut, making it more difficult for your immune system to function normally and distinguish harmful bacteria from harmless.
- Childhood diet: There is some evidence that the foods you are exposed to as a child can determine whether you have allergies in later life. Early introduction to common allergenic foods can prevent you from developing an allergy to that food. For example, eating peanuts in the first 11 months of your life can cut the risk of peanut allergy by up to 80 per cent.
How can you get diagnosed if you think you may be allergic?
Tests which measure the presence of allergen-specific IgE antibodies are used to diagnose allergies. The two most common tests are the skin prick test and the specific IgE blood test. However, detecting the antibodies only indicates that you have been exposed to an allergen, and many people will test positive for IgE antibodies even if they have not experienced a reaction. Therefore a reliable allergy diagnosis depends on both testing and on an allergy-focused history. If the allergy history and the allergy tests give a conflicted result a provocation test may be necessary. This is carried out in hospital, and you are exposed to the suspected allergen under closely monitored conditions to see if you have an allergic reaction.
What treatment is available?
“Treatment depends on the severity of the allergy – you may be able to manage it by avoiding the allergen, or you may need a form of medication or therapy,” said Dr North. “Most allergic reactions are not extreme and the impact of an allergy can be reduced effectively by reducing exposure. Treatments offered include antihistamines, steroids and emollient creams, which all work by easing the symptoms rather than curing the condition and can make a huge difference to your health and wellbeing.”
A small number of people experience a severe allergic reaction called anaphylaxis which is usually triggered by exposure to insect stings, drugs or certain foods. Anaphylaxis is a life-threatening condition which requires immediate emergency treatment using adrenaline.