What is hay fever?
Hay fever is usually an allergic reaction to pollens of
trees, grasses, and weeds. Sometimes it is an allergy to
mold spores. Hay fever may occur any time of the year. It
generally occurs in the spring, summer, or fall. Hay fever
is also called seasonal allergic rhinitis.
How does it occur?
Allergic symptoms result from reactions of your body to
substances that it sees as foreign. Substances that cause
an allergic reaction are called allergens.
The allergens that cause hay fever are pollen and mold.
They float in the air and are spread by the wind. The type
of pollen in the air depends on the growing season and area
of the country. Tree pollens cause most spring hay fever.
In the summer, grass and some weed pollens are usually the
cause. From late summer to the first frost, other weed
pollens cause hay fever.
The parts of the body that may be affected by hay fever are
the eyes; the lining tissue of the nose, sinuses, and
eustachian tube (which connects the middle ear with the back
of the throat); and, less often, the lungs. When the pollen
or molds come into contact with these tissues in an allergic
person, cells in the tissues release a chemical called
histamine. Histamine causes the tissues to itch, swell, and
produce more mucus or tears than is normal.
As many as 1 in 10 people suffer from hay fever at some time
in their lives. Hay fever is more common in people with
other allergic conditions such as asthma or eczema. Hay
fever tends to run in families.
What are the symptoms?
Common symptoms of hay fever are:
- sneezing
- stuffy or runny nose
- itchy nose, throat, or ear canals
- ear congestion
- itchy, watery eyes
- postnasal drainage.
Other symptoms are:
- shortness of breath, especially with exercise or exertion
- coughing
- wheezing.
How is it diagnosed?
Your healthcare provider will ask about your history of
symptoms. If your symptoms occur just in certain seasons,
your healthcare provider will suspect that you have hay
fever. A check of your ears, nose, throat, and lungs may
confirm the diagnosis.
Because the treatment for most cases of hay fever is the
same, regardless of what you are allergic to, allergy
testing is usually not necessary unless you need allergy
shots.
How is it treated?
If you know what you are allergic to--pollens, for
example--you can try to avoid the allergens. For example, using an
air conditioner rather than an attic or window fan lessens
the amount of pollen that gets into your home.
Many hay fever symptoms are so mild that they need no
treatment. Or you may just need to take a nonprescription
medicine once in a while. If you need further treatment, a
variety of medicines are available, such as decongestants,
antihistamines, and steroid nasal sprays.
Decongestants shrink the swollen lining tissues of the ear,
nose, and sinuses. Possible side effects of decongestants
are trouble sleeping, rapid heart rate, and elevated blood
pressure. They should be used with great caution in older
adults.
Antihistamines fight the effects of histamine on your
tissues. You may need to take these medicines only when
your symptoms are bothering you. In more severe cases, you
might take them daily during your allergy season(s) to
prevent symptoms.
There are different types of antihistamines. In older
adults, nonprescription antihistamines, such as
diphenhydramine (Benadryl) and chlorpheniramine
(Chlor-Trimeton), are more likely to cause side effects, such as
drowsiness, confusion, dizziness, dry mouth and eyes,
constipation, trouble urinating, and worsening of glaucoma.
Newer antihistamines, such as azelastine (Astelin),
cetirizine (Zyrtec), fexofenadine (Allegra), loratadine
(Claritin), and desloratadine (Clarinex), are safer but may
cause confusion. Ask your healthcare provider to recommend
an antihistamine.
It is safe to take antihistamines and decongestants together
unless you have had a bad reaction from taking either type
of medicine.
If antihistamines do not help eye symptoms caused by your
allergy, your healthcare provider may prescribe eye drops.
Prescription nose sprays containing steroid medicine are
very effective in preventing or minimizing nasal and sinus
congestion, runny nose, and postnasal drainage. A
nonprescription nose spray containing cromolyn is also very
effective. These nose sprays work best to relieve symptoms
if you use them on a regular basis during the allergy
season.
Other nonprescription nose sprays with the active ingredient
oxymetazoline, such as Afrin, may actually make nasal
congestion worse after several days of use. This type of
spray is not recommended.
Symptoms that affect your breathing are treated with
medicines used to treat asthma, such as:
- quick-acting, inhaled bronchodilators to treat symptoms
- other types of inhaled medicines to prevent symptoms.
If your symptoms bother you a lot despite the medicines you
are taking to treat the hay fever, or if you often have
complications, such as ear or sinus infections or asthma
attacks, your healthcare provider may suggest allergy
shots. You will need tests for specific allergies. For
most people the best tests are skin scratch or prick tests.
For these tests a healthcare provider places tiny amounts
of suspected allergens under your skin and looks for
reactions. These allergy tests may find which allergens are
causing your symptoms.
For your allergy shots, a mixture is prepared that contains
the allergens identified in your allergy tests. The mixture
is injected into your skin in tiny but increasing amounts
over the course of many months. Over time, the shots make
you less sensitive to the allergens. Usually after 4 to 6
months of allergy shots you will begin to have relief from
your allergies. However, you will probably need to continue
the shots for 2 to 3 years or longer.
How long will the effects last?
Allergies last different amounts of time for each person.
Allergies can develop at any age. Children with hay fever
may continue to have seasonal allergies as they grow older
or the allergies may go away over time. If you start having
allergies as an adult, you will probably continue to have
them. However, the allergies may stop if you move to an
area where the substances causing your allergies are not
present.
How can I help myself?
- Follow your healthcare provider's advice for controlling
your hay fever.
- If you usually get symptoms during housecleaning or yard
work, wear a mask (available in drugstores) over your
nose and mouth during these chores. Don't stay in the
house when someone else is cleaning your house.
- Vacuum your carpets, curtains, and soft furniture often.
Clean your hard floors with a damp mop or cloth.
- Remove any mold you find in your home. Use paint rather
than wallpaper on your walls. Don't put carpet in damp
areas.
- Stay away from trees and grasses as much as you can in
the pollen season.
- Keep doors and windows shut in the pollen season. Use an
air conditioner, if you have one, in your house and car.
- Shower or bathe at night to remove pollens or other
allergens from your hair and skin.
What can be done to help prevent hay fever?
There is no known way to prevent allergies. However, some
research has shown that breast-fed babies may be less likely
to develop allergies and asthma. Also, if your family has a
very strong history of allergies, you might try to avoid
your family's most common allergens. For example, you might
need to stay away from cats. This might help stop you from
developing severe symptoms.
This content is reviewed periodically and is subject to
change as new health information becomes available. The
information is intended to inform and educate and is not a
replacement for medical evaluation, advice, diagnosis or
treatment by a healthcare professional.
Copyright © 2007 McKesson Corporation and/or one of its subsidiaries. All Rights Reserved.