Nasal allergies and asthma are similar conditions in different parts of the
- As many as 78% of asthma patients have nasal symptoms.
- As many as 38% of nasal allergy patients have asthma.
- Treating the allergic inflammation in the nose may help prevent asthma
or reduce asthma severity and lower airway hyper-responsiveness.
Hay fever (allergic rhinitis) involves an allergic reaction to pollen.
A virtually identical reaction occurs with allergy to mold, animal dander,
dust, and similar inhaled allergens. The pollens that cause hay fever vary
from person to person and from region to region. Pollens that are carried by
bees from plant to plant are seldom responsible for hay fever because the grains
are large and have a waxy coating. Tiny, hard-to-see pollens carried by the
wind are more often the cause of hay fever.
Examples of plants commonly responsible for hay fever include:
- Trees (deciduous and evergreen)
- Most flowers
In addition to individual sensitivity and geographic differences in local
plant populations, the amount of pollen in the air can be a factor in whether
hay fever symptoms develop. Hot, dry, windy days are more likely to have increased
amounts of pollen in the air than cool, damp, rainy days where pollen is washed
to the ground.
When an allergen such as pollen or dust is inhaled by a person with a sensitized
immune system, it triggers antibody production; these antibodies bind to cells
that contain histamine. Histamine and other chemicals are released by these
cells when the antibodies are stimulated by allergens. This causes itching,
swelling of affected tissues, mucus production, muscle spasms, hives, rashes,
and other symptoms. Symptoms vary in severity from person to person.
- Itching of the nose, mouth, eyes, throat, skin, or any area
- Runny nose (rhinitis)
- Smell - impaired
- Sore throat
- Stuffy nose (nasal congestion)
- Watery eyes
History is important in diagnosing hay fever, including whether the symptoms
vary according to time of day, the season, exposure to pets, diet changes,
or other sources of potential allergens.
Skin testing is the most common method of allergy testing. This may include
intradermal, scratch, patch, or other tests. Occasionally, the suspected allergen
is dissolved and dropped onto the lower eyelid (conjunctiva) of the eye as
a means of testing for allergies.
There are no specific blood tests that are commonly used to diagnose hay fever.
The best "treatment" is to avoid what causes your allergies in the first place.
It may be impossible to completely avoid everything you are allergic to, but
you can often take steps to reduce your exposure.
Medication options include the following:
- Short-acting antihistamines, which are generally non-prescription,
often relieve mild-to-moderate symptoms but can cause drowsiness. In addition,
these antihistamines can blunt learning in children (even in the absence
of drowsiness). An example is diphenhydramine (Benadryl).
- Longer-acting antihistamines cause less drowsiness and can be equally
effective, and usually do not interfere with learning. These medications
include fexofenadine (Allegra), cetirizine (Zyrtec), and loratadine (Claritin).
- For people with symptoms not relieved by antihistamines alone, nasal
corticosteroid sprays are very effective and safe. These prescription
medications include fluticasone (Flonase), mometasone (Nasonex), and triamcinolone
- Decongestants may also be helpful in reducing symptoms such as nasal
congestion, but should not be used for long periods.
- Cromolyn sodium is available as a nasal spray (Nasalcrom) for treating
hay fever. Eye drop versions of cromolyn sodium and antihistamines are available
for itchy, bloodshot eyes.
Allergy shots (immunotherapy) are occasionally recommended if the allergen
cannot be avoided and symptoms are hard to control. It includes regular injections
of the allergen, given in increasing doses (each dose is slightly larger than
the previous dose) that may help the body adjust to the antigen.
Symptoms may sometimes be prevented by avoiding known allergens. Most trees
produce pollen in the spring, grasses and flowers usually produce pollen during
the summer, and ragweed and other late-blooming plants produce pollen during
late summer and early autumn. During the pollen-producing times (pollen season),
people with hay fever should remain indoors in an air conditioned-atmosphere
whenever possible. For people that are sensitive to certain indoor allergens,
dust mite covers for mattresses and pillowcases are recommended, as well as
avoidance of culprit pets or other triggers.
American Academy of Allergy, Asthma & Immunology (AAAAI). The Allergy
Report: Science Based Findings on the Diagnosis & Treatment of Allergic
Disorders, 1996-2001. Milwaukee, Wis: American Academy of Allergy, Asthma & Immunology
(AAAAI); 2001. (2007 updated version available online at www.theallergyreport.com.)
Spector SL, Nicklas RA, Chapman JA, et al. Symptom severity assessment of
allergic rhinitis: part 1. Ann Allergy Asthma Immunol. 2003 Aug;91(2):105-14.
Review Date: 5/16/2007
Reviewed By: Alan Greene, M.D., F.A.A.P., Department of Pediatrics, Packard Children's Hospital, Stanford University School of Medicine; Chief Medical Officer, A.D.A.M., Inc.
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