Postnasal allergy, also known as allergic rhinitis, is a fairly common condition that affects in one in five people in the United States. Allergic rhinitis is caused by a wide range of allergens and irritants, and can be chronic or acute. The symptoms are manageable; however, they are an annoyance for adults and older children. Avoiding the causative trigger or allergen and finding the right treatment makes a huge difference in managing this condition.
Immune Reaction to Allergen
Postnasal allergies are caused by an allergic reaction to allergens or irritants viewed by the immune system as harmful. The immune system activates and recruits pro-inflammatory immune cells, primarily mast cells and basophils, to the mucous membrane of the nasal cavity, and causes the release of chemicals such as histamine into the bloodstream. Histamine is an important immune mediator that dilates and increases the permeability of blood vessels in the nasal cavity. This enables fluid to leak from blood capillaries into nasal tissue, resulting in the accumulation of fluids into nasal tissues, and other associated symptoms.
Causes of Postnasal Allergies
Allergic rhinitis, also known as seasonal hay fever, is caused by allergens such as tree pollen in the spring; grass and weed pollen during late spring, summer and fall; and spores from mold and fungi during warm weather months. Perennial allergic rhinitis occurs year round, and is caused by indoor allergens such as cockroaches and dust mites, animal dander, and spores from indoor or outdoor molds and fungi. Non-allergic rhinitis is caused by exposure to irritants or chemicals including cigarette smoke, smog, air pollution, fluctuations in temperature as well as strong fragrances and odors such as perfume and detergent.
Symptoms of Postnasal Allergies
The release of histamine into the nasal mucous membrane and bloodstream results in a wide array of symptoms including nasal congestion, postnasal drip, runny nose, sneezing and itching. Increased permeability of the nasal capillaries engorges the surrounding tissue with fluids. Blockage of the nasal passages, sneezing, nasal itching and a runny nose with thin, watery discharge is commonly observed. Individuals also experience facial pain and sinus pressure, in addition to a decreased sense of taste and smell. Watery and itchy eyes as well as swelling of the skin beneath eyes are common symptoms. The throat and ears are also effected, and you may experience an itchy sensation in the throat and roof of the mouth, voice hoarseness and itching of the ear and throat.
Treatment for Postnasal Allergies
The first line of the treatment for postnasal allergies is avoiding exposure to the allergen or trigger. Your physician may recommend different forms of medication therapy to reduce the associated symptoms. Washing the nasal cavities with a saline spray or a water salt solution helps to remove the allergen or irritant from the nose and reduces nasal dryness, congestion, sneezing and draining down the back of the throat. Nasal corticosteroids such as Flonase, Veramyst or Nasonex may be prescribed by your physician to treat and prevent nasal inflammation, and reduce symptoms such as a runny nose and nasal itching. Antihistamines block the action of histamine, and may be prescribed to alleviate a runny nose, itching and sneezing. Your physician may also recommend over-the-counter or prescription decongestants to help with nasal blockage and congestion.
References
- MayoClinic.com; Hay fever; April 2010
- MayoClinic.com; Nasal congestion; September 2010
- American College of Allergy, Asthma and Immunology: Allergic Rhinitis (Hay Fever)
- UpToDate; Patient information: Allergic rhinitis (seasonal allergies); Richard D. deShazo, M.D., Stephen F. Kemp, M.D.; October 2010
- National Institute of Allergy and Infectious Diseases; Airborne Allergens; April 2003
