Allergies

What are allergies?

Allergies are an overreaction by your body to a specific trigger that doesn’t cause the same reaction in other people. Your body produces an immune response to something that it wrongly views as a threat. This shows as a reaction in your skin, sinuses, digestive system or your airways (or a combination of these).

The severity of allergies can vary from person to person. For some people, an allergic reaction can be a relatively mild reaction, but others can experience anaphylaxis, which is a potentially life-threatening situation. Allergies can appear at any time in your life, even if you haven’t previously experienced them.

Some of the most common allergies include: food allergies, dermatological allergies (when your skin comes into contact with something that causes a reaction), grass and tree pollen (also known as hay fever), animal hair, mold, latex, dust mites, medicines, household chemicals and insect bites.

Who gets allergies?

Allergic reactions can happen to anyone at any time. It’s thought that they can be hereditary and if you have parents who also experience allergies you may also experience them too. You can also be allergic to more than one thing – even things that are seemingly completely unrelated.

Allergies are most common in children and they can fade in severity as you get older, though they don’t always fade in this way. However, sometimes the opposite can happen and you can develop new allergies in adulthood, even if you’ve never previously experienced a reaction to something before.

How common are allergies?

Allergies are really common. It’s estimated that there are millions of people around the world who are affected by allergies at some point in their lives with as much as 40% of the global population showing sensitivity to factors in their environment.^[1]

More and more people are suffering from allergies each year, particularly food allergies.^[2] Where you live and your lifestyle can have an effect on your allergies, especially if you have certain types of environmental or food-based allergies.^[3]

What causes allergies?

The exact reasons why we experience allergic reactions are relatively unknown, especially the reasons for being allergic to some things but not others. Our environment plays a part in the cause of these allergic reactions, as do our genetics.^[1]

One theory is that a lack of exposure to germs at a young age can stop the immune system from working properly. This means that it perceives certain things in your environment as a threat and overreacts with an immune response. It’s even thought that the size of your family can have an impact, as larger families have more exposure to different types of bacteria.^[2]

When you experience an allergic reaction, it’s your body’s reaction to something in the environment that it decides is a threat. Your white blood cells react to protect your body and release histamines, which is what causes the visible symptoms of an allergic reaction, such as inflammation and swelling.

What are the symptoms of allergies?

There are some common symptoms of an allergic reaction. These can vary from person to person, and you might experience some of them or all of them during an allergic reaction. Common allergy symptoms include:

• skin reactions such as dry, red and cracked skin, or an itchy rash that may be raised or appear red
• sneezing, coughing or wheezing
• a tight chest or shortness of breath
• swelling of the lips, tongue, eyes or other parts of the body
• sickness, diarrhea or nausea

The symptoms of an allergic reaction will depend on how you have come into contact with an allergen and whether or not you’ve ingested, inhaled or touched whatever’s triggered your allergy. Symptoms will also vary in severity from person to person and can even be different each time your body reacts.

Can allergies lead to other problems?

Most allergy reactions are pretty mild and don’t cause any other health problems. But they can be frustrating and uncomfortable to deal with. If you haven’t experienced an allergic reaction before it can feel overwhelming or unexpected.

Some allergic reactions can be really serious. A severe allergic reaction can lead to anaphylaxis, which can be life-threatening. It’s where the body seriously overreacts to an allergen by causing breathing difficulties, wheezing, feeling lightheaded, a fast heartbeat, clammy skin, confusion and even collapsing or becoming unconscious, as well as other symptoms.

If you experience these symptoms, you should call an ambulance immediately, and whatever’s causing the reaction should be avoided. If this has happened previously, a person may carry an emergency adrenaline auto-injector pen (also known as an EpiPen) with them to help deal with symptoms. Anaphylaxis is a serious medical emergency.