Seasonal allergic rhinitis, sometimes known as hay fever or simply allergies, is an allergic response to pollen (the male component of the plant reproductive system) or other microscopic substances that are present only at certain times of the year. Allergic rhinitis can also be perennial (year-round).
In the spring, pollinating trees are most often responsible for causing allergic rhinitis. Over the summer, grasses and weeds mainly produce the offending pollen. And in the fall weeds are mostly to blame, with ragweed being the main culprit. Allergic rhinitis can also be caused by mold releasing its reproductive cells, called spores, from late March until November, usually peaking in late summer and early fall. But they can also be present year round.
Perennial allergic rhinitis is caused by agents that are present throughout the year, such as dust mites, mold, animal dander, and feathers. These irritants can be found in pillows, down clothing, draperies, upholstery, thick carpeting, and bedding.
It is common for people who suffer from allergies to be allergic to more than one pollen or agent.
What Are the Symptoms of Allergic Rhinitis?
In cases of allergic rhinitis, your body's immune system interprets the allergen (pollen, mold, dander, etc.) as an "invader" and responds by releasing chemicals such as histamine into the bloodstream.
Histamine causes inflammation (swelling and redness) of the sinuses, nose, and mucus membranes of the eyes and triggers sneezing. The swelling reaction is designed to block the allergen from entering the body and sneezing is a method to expel it out of the body. Histamine also allows fluids to enter the nasal tissue, resulting in congestion and an itchy, runny nose.
People with allergic rhinitis have sudden sneezing and a watery nasal discharge. Symptoms can occur at all stages of life, but most people develop them before reaching 30 years of age.
How Do I Find Out What Causes My Allergies?
The season in which your allergies occur will narrow the list of possible culprits. To pinpoint the cause, a doctor, typically a board-certified allergist, may perform a skin test to determine which substances (allergens) cause a reaction.
The skin prick test involves placing small drops containing extracts of potential allergens on your arm or back, and then scratching the surface of your skin so the extract can interact with immune cells in the skin. Typically these extracts have been developed and tested over time to ensure that the specific concentrations are appropriate and that they typically will only cause a reaction in those who are sensitive to an allergen. Those areas that become red and itchy indicate which substances trigger an allergic response by your immune system.
Your doctor may also perform a blood test to check the levels of antibodies produced by your immune system. Elevated levels of certain antibodies can identify particular allergies. Each test has its own advantages and disadvantages that should be discussed with your doctor when selecting which tests are best for you.
