How is the respiratory system involved with allergies?
The main role of the respiratory system is to work closely with the heart and blood to take up oxygen from the air we breathe and dispose of waste gases, primarily carbon dioxide. The nose plays a key role in respiratory system function as it serves as a passage for airflow, helps to heat and moisten external air before it enters the lungs, and tiny hairs and mucous that line the nasal passages help to trap unwanted dust, pollen and other microscopic particles before they enter the body.
Allergic rhinitis (hayfever) is an allergic condition of the respiratory tract. A person with hayfever is allergic to some of the particles that get trapped in the nose such as pollen.
What happens with a hayfever reaction?
When a person breathes in a substance through their nose that they’re allergic to like pollen or dust mites (known as allergens), the body reacts quickly. Antibodies called immunoglobulin E (IgE) which are found on the surface of mast cells in the tissues that line the nose, attach themselves to the allergen. This triggers the release of histamine and other inflammatory chemicals and results in hayfever symptoms. These chemicals stimulate the mucous glands which leads to increased secretions, cause blood vessels to dilate causing congestion and pressure, and stimulate the sensory nerves which triggers sneezing and itching. All of these events can occur within minutes of exposure to an allergen. Hayfever symptoms can persist for hours or even days and can be very disruptive for hayfever sufferers sometimes impacting on their ability to sleep and concentrate in addition to making them feel generally tired or unwell.