An allergy occurs when the body becomes oversensitive to various allergens or triggers. This can be from food, the environment, chemicals, plants and skin products to name a few. It occurs when our immune system has an inappropriate response to a non-pathogenic foreign substance. Symptoms can include itchy skin or eyes, rash, watery eyes, runny nose, stuffed up feeling, headache and even in severe cases an anaphylactic reaction where we cannot breathe properly.
Symptoms depend on the type of allergy, but may include:
- Runny nose/stuffy nose/nasal congestion
- Itchy, watery eyes
- Dry mouth
- Sore/scratchy throat
- Skin rash
- Swelling of face, lips, eyes or tongue
- Difficulty breathing
- Allergic asthma
- Anaphylactic shock
Many of these symptoms are also present with many other medical conditions, so it is important to see your doctor to diagnose your symptoms. You should never self-diagnose.
How allergies develop is still not fully understood. According to the Canadian Allergy, Asthma and Immunology Foundation, an estimated 20-30% of Canadians suffer from allergies. There are believed to be many factors that contribute to the formation. The universal understanding of allergies is that a normally harmless substance is activating the immune system when it should not be. This could mean that the immune system is either not trained properly or not working properly.
There are many theories about why allergies occur:
What is the Hygiene Hypothesis?
This is based on the idea that decreased exposure to bacteria and infections during infancy in early childhood prevents the immune system from developing the appropriate defences it needs to understand the difference between good and bad stimuli later in life. Little or no exposure to allergens makes it difficult for the body to process, or to develop a tolerance to.
The intestinal mucosa is an important part of the immune system – it forms a barrier between the outside world and the inside of the body, only letting certain things pass between its walls to enter our bloodstream. If the intestinal mucosa becomes inflamed or damaged it loses its ability to properly filter out what should pass through the barrier and what shouldn’t. This leads to substances passing through the gut wall into the bloodstream that should not be.
Our psychological state also has a large impact on both the health of our guts and the health of our immune system. Stress is characterized by being in a sympathetic state known as “fight or flight”. This constant state of stress and sympathetic stimulation can have a profound effect on the optimal function of our immune and digestive systems. In this sense, stress and other psychological factors, especially when they become chronic, may trigger or worsen allergic symptoms.
Histamine is a molecule that is released by our cells that promotes allergic immune responses. When the body senses that there is a foreign substance that needs destroying, it releases various molecules to mount its defences. Histamine is released when the body believes it is responding to an allergen. Histamine is sent from one cell to another creating a larger and larger response to the stimuli and increasing the intensity of the symptoms associated with allergies.
Antihistamine medication is used during allergies to try and stop the production of histamine and therefore stop the immune system from mounting a larger response. Histamine is produced naturally in the body, but it can also enter the body in different ways. Some foods contain histamine including alcohol, nightshades (eggplant, tomatoes), tuna and fermented foods including dairy products, grains, soy, meats and kombucha. A diet high in foods that contain histamine can worsen symptoms of allergies in someone who is susceptible to them.
Some common allergens include, but are not limited to:
- Plants - pollen from grasses and plants
- Food - seafood, tree nuts, eggs, milk, sesame and soy products
- Insects - dust mites, bees, wasps
- Medicines - prescription antibiotics like penicillin, non-prescription medications like aspirin
- Animal dander - fur and skin flakes from domestic pets like cats and dogs
- Chemicals - household cleaning products, skin lotions and soaps
Seasonal allergies also referred to as hay fever, are a problem for many. Some experience mild symptoms, while others' symptoms are almost debilitating. Seasonal allergies most commonly occur in the spring, when the weather changes and environmental substances such as pollen become airborne.
Pollen is released into the air by trees, grasses and other plants when they bloom to fertilize other plants. Pollen can travel through the air at impressive lengths (miles). This is why pollen counts tend to be higher on windy days, while counts are lower on rainy days.
When the body detects pollen in someone who is allergic, it releases antibodies to attack the allergens. This leads to the release of chemicals called histamines into the blood. Histamines trigger the itchy, watery eyes, runny nose, sneezing and other symptoms associated with hay fever.
There are over the counter, non-prescription medications including oral antihistamines, nasal sprays, eye drops, and decongestants that can help with the symptoms of hay fever. However, many of these hay fever treatments do have side effects associated with them depending on which medication is used. For example, sedating antihistamines are very commonly used to relieve symptoms of hay fever. While there are some non-sedating (non-drowsy) options, most oral antihistamines will cause extreme tiredness and may make it impossible to operate a vehicle or heavy machinery after taking.
Various home remedies have been linked to decreasing the symptoms of allergies. Here are a few you can try:
Take a steam bath or steam shower
The steam can help to open the airways if the sinuses are congested. Adding peppermint or eucalyptus essential oils into the steam can help to open the airways and clear the sinuses when they are breathed in.
Rinse the nasal passages
Using a saline solution to rinse your nasal passages will moisten the nasal mucosa help ease the itching and wash the allergens out.
Eat a diet rich in fruit and vegetables
Fresh fruit and vegetables contain vital nutrients including vitamin C that help to support the immune response and decrease histamine in the body. This type of diet including healthy fats is said to be anti-inflammatory as it decreases the unnecessary inflammation the immune system is causing in the body.
Try taking herbs
Herbs including nettle tea have this same stabilizing effect on the immune system helping to decrease the symptoms associated with an allergic reaction.
Pay attention to pollen counts
During hay fever season paying attention to the pollen count through various weather, by looking at weather sites which might be helpful in avoiding days and areas that might trigger hay fever symptoms.