Allergic Rhinitis (Seasonal Allergies / Hay Fever)
Allergic rhinitis is a condition mainly characterized by runny nose, sinus congestion, sneezing, and itching after being exposed to an allergen.
Allergic Rhinitis (Seasonal Allergies / Hay Fever) falls under theEar, Nose & Throatcategory.
After exposure to the allergen (something that triggers allergic reactions), people may experience sneezing, a runny/stuffy nose, itchy/red/watery eyes, and coughing. Symptoms may range from a minor annoyance that lasts for a short season, to severe and last a long time leading to sleep disturbances.
Diagnosis is based upon a thorough history and physical examination from a healthcare provider. To confirm a diagnosis, nasal corticosteroids may be prescribed to see if there is a reduction in symptoms. In some cases, blood tests measuring allergy sensitivity or skin prick testing (a procedure where a small amount of the allergen is exposed to the skin) are also used. Rarely, imaging can be used, such as a CT scan, but this is typically not necessary.
Common treatments include medications such as antihistamines, decongestants, and/or intranasal or oral corticosteroids. Another treatment includes exposing the body to small amounts of the allergen (either through a tablet or an injection) in order to develop a better immune response over time, resulting in decreased symptoms.
One of the risk factors for developing allergic rhinitis later in life is having a food allergy during early childhood (<2 years old). It is believed that introducing foods associated with allergy (e.g., peanuts, gluten, eggs, dairy, and shellfish) to infants may reduce the risk of developing food allergies, and ergo allergic rhinitis later in life. However, the evidence surrounding early allergenic food introduction and developing allergic rhinitis is weak. Currently, there are no dietary recommendations for improving allergic rhinitis. 
Aside from medical treatments, symptoms are usually controlled by reducing exposure to allergens in the environment. Irritant exposure can be reduced by using air filters, regular house cleaning, saline sinus rinses, and wearing masks. There is some weak evidence that acupuncture may improve symptoms of allergic rhinitis. 
In allergic rhinitis, the immune system is hypersensitized to an allergen and responds with an overreaction to remove the allergen from the body. The body releases histamine and other chemical mediators that cause symptoms of allergic rhinitis (sneezing, runny nose, etc) in an attempt to neutralize and remove the offending substance. It should be noted that this reaction by the body to allergens is typically maladaptive, as the offending allergen is rarely dangerous.