Allergies & Asthma -- The Ear Connection
by Lorraine Short
Assistant Editor, Hearing Health
There's a whole lot of sneezing (and wheezing) going on! Allergies and
asthma are on the rise at an alarming rate worldwide. Reaching epidemic
proportions, allergies reportedly attack 40 million people in the United
States alone-double the amount of 25 years ago! Asthma, long-believed
to be related to emotional or psychological factors, is now considered
to have a strong connection to allergies. Its rates have also doubled,
with 15 million Americans now waging an ongoing battle to breathe. Sinus
disease, often related to allergies, is now our number one medical problem.
Theories abound about the culprits behind this sharp increase. Many focus
on our extensive exposure to internal pollution while spending too much
time parked in front of the TV or computer screen. In inner city or other
areas with heavy cockroach infestations, toxins from the decaying insects
are potent additions to the mix. Poor construction often allows damp areas
to persist which encourage the growth of mold. Growing dependence on prepackaged
meals increases exposure to foods and additives that may cause reactions.
Add to all of that the more familiar irritants that populate our outside
environment (e.g., pollens of ragweed, trees, and grasses), and it is
no wonder that nearly 25 percent of the population is struggling with
frequent bouts of allergy symptoms.
As we learn about these troubling developments, we wonder about their
effects on hearing, and whether there is anything new to report on the
connection between allergies, asthma, and audiological problems like tinnitus
or Meniere's disease. We asked Nicholas G. Nonas, M.D., to update us on
the relationship between allergies and the ear. Nonas is a specialist
in Ear, Nose, Throat Allergy & Environmental Medicine.
Dr. Nonas begins by noting that allergies and certain types of asthma
are basically a result of a hypersensitive immune system responding to
foreign substances (allergens) which it mistakenly identifies as harmful
to the body. These allergens enter the body through the nose, mouth, eyes,
or skin. Specialized cells found in the stomach, the lining of the upper
and lower respiratory tracts, and the endolymphatic sac in the inner ear
intercept the intruders. Over 20 chemicals (mediators), including histamines
and leukotrines, are produced in the process, inducing inflammation and
other allergic reactions.
Symptoms depend on the organ that is targeted by the mediators. In the
nasal passages, it's hay fever; in the sinuses, sinusitis; on the skin,
hives or eczema; in the intestines, indigestion and/or diarrhea; in the
lungs, coughing or asthma; in the brain, migraines; and in the middle
ear, chronic ear infections. Based on results of experiments within the
last decade or so, Nonas strongly suspects that there is an allergic component
in the development of inner ear disorders including sensorineural hearing
loss and Meniere's disease.
Genetics play a role in allergies and allergic asthma, but that role
is far from clear cut. Perhaps the most that can be said is that they
appear to "run in the family," that individuals can be predisposed to
allergies, and that susceptibility may depend on the amount and type of
allergens that happen to be in the immediate environment. "And although
we usually blame something in the air for our symptoms," Nonas says, "my
own work with allergic ear diseases suggests to me that food allergies
are the problem in about two-thirds of the cases, even when there are
respiratory or auditory symptoms. Multiple allergies are often involved,
since most food allergens are common things like wheat, milk, eggs, and
corn. It's very difficult to avoid exposure to them. Many people eat them
on a daily basis and are in a chronic reaction."
Conductive hearing loss can result from allergic responses that increase
fluid in the middle ear. Accompanying inflammation of the Eustachian tubes
prohibits relief of fluid pressure. This is a common problem among young
children with allergies, compounding the constriction already present
in their not-fully developed tubes. Although this is usually a temporary
or reversible hearing loss, It is imperative to keep the periods of decreased
hearing at a minimum during the language development years.
If a child has repeated ear infections, it is essential that s/he be
evaluated for allergies. If inhalant allergies are diagnosed, it may be
necessary to alter the environment in the rooms where the youngster spends
the majority of the time: take carpeting out of the bedroom and inside
play areas; damp mop, dust, and vacuum frequently; and perhaps relocate
the family pet.
"If a food allergy diagnosis is made," Nonas warns, "it is very important
to match the nutritional content of replacement foods with those being
avoided. Dietary changes are difficult and require a team approach to
succeed." Early treatment with an antihistamine can block the initial
reaction to the allergen, while using a decongestant may decrease swelling
enough to avoid infection, repeated courses of antibiotics, and temporary
hearing loss. In Moderate-to-severe cases, Immunotherapy--a series of
shots in gradually increasing doses of allergen Extract--may be initiated
as early as age five. Resistance to the allergy develops over the course
of treatment in at least 70 percent of cases, Generally it takes from
three to five years to succeed.
Adults also experience fluctuating hearing from fluid build-up and Eustachian
tube dysfunction due to allergies, but less frequently. According to Nonas,
it can be a more complicated situation which usually involves both indoor
and food allergens. A combination of environmental and dietary changes
and treatment with antihistamines and/or decongestants may remedy hearing
changes. In severe cases, immunotherapy may be the best alternative.
A connection between allergies and inner ear disorders was first suggested
in the 1920s and has been hotly debated over the years. Nonas carefully
points out there is no definitive proof as yet, but there are some interesting
developments. He cites a noteworthy study of 93 Meniere's patients at
House Ear Institute in 1992. Test subjects were chosen whose symptoms
of vertigo, tinnitus, and fluctuating hearing loss seemed related to seasons,
weather changes, or a certain food; who had known allergies; and who had
involvement of both ears. After testing and diagnosis, immunotherapy was
used for those patients with inhalant allergies while diet restrictions
were applied to those with food allergies.
During the two-year follow-up period, significant changes occurred. Among
the entire group, 62 percent reported decrease in frequency and severity
of vertigo attacks, while 50 percent had an improvement in tinnitus. Fluctuating
hearing loss also showed improvement in 60 percent of the cases. In a
sub-group of 21 patients for which there is more detailed information,
a remarkable 86 percent reported complete or substantial control of vertigo.
Nonas predicts that continued research will substantiate these results,
offering hope that individuals with early symptoms of Meniere's will benefit
from allergy treatment. It may even be possible to avoid or lessen associated
sensorineural hearing loss which is usually not reversible.
Several new prescription and non-prescription products offer relief to
people with allergies and asthma. Steroids routinely used to reduce inflammation
are now joined by a new class of drugs that block the action or even the
production of leukotrines (which trigger swelling). Vaccines are currently
in the testing stages for a couple of the worst allergic offenders: cat
dander and ragweed. Derived from DNA peptides of these allergens, as few
as four injections of one vaccine has brought relief to people with severe
reactions. Nonas heralds these advances but points out that it is not
known how these and future allergen-specific vaccines will improve results
for people with multiple allergies.
Increased understanding of the widespread impact of allergies is underway.
Often called the "great masquerader," allergy should be more widely suspected,
diagnosed, and treated as a result of new findings. "Certainly allergies
should be considered as a possible contributor in many audiological problems,"
Nonas emphasizes. "Talk it over with your otolaryngologist. Working together,
you may be able to stabilize or improve your hearing, tinnitus, or Meniere's
For a referral or more information, contact: American Academy of Otolaryngic
Allergy, 8455 Colesville Rd., Ste. 743, Silver Spring, MID 20910; FAX
301-588-2454; E-mail AAOA@aol.com
Dr Nonas, a member of AAOA and the American Academy of Family Physicians,
practices in Englewood, Colorado.