Allergic rhinitis, also known as “hay fever,” has nothing directly to do with hay and is not accompanied by a fever.
The most common chronic disease of childhood, it may affect up to 25% of U.S. children.
Hay fever is caused by an overreaction of the immune system to allergens that are harmless to most people.
These allergens trigger the release of histamine in the mucous membranes lining the nasal passages, sinuses and inner surfaces of the eyelids.
This causes inflammation, swelling and fluid production.
The symptoms of allergic rhinitis can include runny nose (and eyes), nasal congestion, postnasal drip, nose (and eye) itchiness, snoring, coughing, sneezing, and eye redness.
The increased blood flow triggered by histamine release can cause dark circles under the eyes and wrinkling of the lower eyelids.
A horizontal crease across the nasal bridge may emerge if children rub their palm upwards against their noses (the allergic salute).
Complications may include mouth breathing (which over time can lead to facial bone and dental growth abnormalities).
Restless sleep (which can cause daytime sleepiness and fatigue), fluid trapping in the middle ear (which can cause hearing problems or lead to middle ear infections) and nosebleeds may also occur.
The tendency for someone to have allergic rhinitis is inherited, but what a person is actually allergic to is not.
Common allergens include pollen (especially from trees, grasses and ragweed), mold spores, dust mites, pet dander and cockroaches.
Seasonal allergies happen when certain pollens are released into the air.
Seasonal allergies are commonly seen in children older than 6.
Perennial allergies are triggered by allergens present throughout the year and are common in younger children.
Allergic rhinitis is diagnosed by a medical history and a physical exam. What allergens a person is actually allergic to, if not evident by history, can be tested for by skin patch testing (or in some cases by specific blood tests).
Treatment of allergic rhinitis includes the avoidance of specific allergens if possible (avoiding certain pets, not being outdoors during peak pollen times, etc.).
Certain medications can be tried such as antihistamines, nasal sprays (antihistamine or corticosteroid), decongestants or leukotriene inhibitors.
Immunotherapy – injecting diluted allergens that a person is allergic to in gradually increasing concentrations – may take years to work.
But it can train the immune system not to overreact to otherwise harmless substances floating in the air.