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Allergy
and Immunology Information
Counting
Pollens. Pollens are the fertilizing elements of
flowering plants consisting of fine powdery, yellowish grains, or
spores. They are carried on the wind, and are a major cause of allergy.
Using a pollen sampler, Dr. Hovanky collects the pollens daily. Via microscope,
she identifies and counts each pollen type and,
three times each week, reports that count to the National Allergy
Bureau. Dr. Hovanky is one of only six counters in Texas certified
nationally by the Aeroallergen Monitoring Network. The Network is
sponsored by the American Academy of Allergy, Asthma, and Immunology, of
which Dr. Hovanky is a fellow. We also report our counts to local media.
Dr. Hovanky's count for the Austin area may be obtained by visiting the web site at
http://www.aaaai.org/nab.
Click here or on the photo below to access the
most current count for the Georgetown area!
Mountain Cedar Allergy.
From December through
February, many people experience an itchy, runny nose, sneezing, nasal
blockage, excess tearing and itchy eyes. Others complain of itching of
the palate, throat, or ears, and post-nasal drainage. Some have fatigue,
mild headache, facial discomfort, sore throat, partial loss of sense of
smell, and sensation of ear plugging. If you experience the above
symptoms every year during these months, the chance is great that you
have Mountain Cedar allergy. Allergy sufferers often describe an obvious
seasonal pattern of the onset of symptoms over the years. This condition
is mostly caused by pollens. Throughout the northern hemisphere, tree
pollens appear from March through May; in central Texas, these are
mostly pollens of: Ash, Oak, Willow, Hackberry, Walnut, Elm,
Hickory, Pecan, Mesquite, and Mulberry. The exception is with the Fall
Elm (or Cedar Elm) tree which pollinates in August, September, and
October. The grass pollen season extends from May through August. Weed
pollens are observed from July through October. Therefore, for most
parts of this country, the atmosphere in the winter months is usually
free of pollens. However, central Texas has pollens of Mountain Cedar in
the winter months. For example, in Georgetown, the Mountain Cedar pollen
count rose from zero on November 3, 1998 to 300 pollens per cubic meter
on December 8, and to 4,890 pollens per cubic meter on January 2, 1999.
 The
culprit is the member of the cypress-juniper (Cupressaceae) family, the
Mountain Cedar, Juniperus ashei (also called Juniperus sabinoides or
Juniperus mexicana). It grows naturally and is the most allergenic tree
in Central Texas. The Mountain Cedar (MC) is an evergreen tree with
grey-brown shredding bark, it grows to a maximum height of approximately
30 feet on the limestone plateaus of central Texas, and in smaller
favorable areas of Texas, New Mexico, northern Mexico, Arkansas, and
Oklahoma. The Junipers have male and female plants, At the ends of its
scale-like leaves, the male tree proliferates numerous reddish-brown
cones 3 to 4 mm in diameter tipped with pollen, while female trees bear
fewer 6 to 8 mm diameter dark blue-green berries (cones). The pollens
from the male tree appear as smoke in the air if the branch is
physically disturbed. Juniperus ashei (Mountain Cedar) dominates most of
the Edwards plateau hill country of central Texas; the trees have become
overgrown and a pest for farmers and ranchers.
The Mountain Cedar generally pollinates from November through March with
the heaviest pollination during December, January, and February. During
this period of heaviest pollination, MC is the only pollen present in
significant amounts in the atmosphere of central Texas. This toxic
pollen is important particularly to those migrants who have never been
exposed to it. Many patients correlate their symptoms with Christmas
Day. National Allergy Bureau (NAB) data shows that in central Texas, MC
pollens appear as early as October, peak in January, remain elevated
until April, and are occasionally seen as late as May.
 The
pollen is very buoyant and may be carried by the air for miles. Among
all the junipers, the MC has received the greatest attention as an
allergen source. The toxic nature of the MC pollen may lie in its
chemical nature. The allergic reactions to MC pollen appear to be
attributable to a single, stable, glycoprotein, with high carbohydrate
and low protein content. This contrasts with the majority of known
allergens in pollen grains, which tend to be a mix of allergenic
glycoproteins having much lower carbohydrate content. The high
carbohydrate content in combination with high density make the pollen of
Mountain Cedar unique in causing allergic rhinitis.
In addition to making a person feel ill due to allergies, this condition
can interfere in a variety of ways with carrying out one's day to day
responsibilities. Loss of sleep, limitation of activities, diminished
productivity, poor concentration, emotional distress, irritability,
fatigue, and practical problems such as repeated nose blowing and nose
rubbing, all impact negatively on ability to carry out physical, social
and work/school responsibilities effectively. Similar to other pollen
allergens, MC pollens contact the lining tissue of a person's eyes,
nose, and lungs. Therefore reducing the duration of exposure to these
pollens is important.
Keep windows and doors closed. Use a ventilating system, if necessary,
on the indoor cycle (closed vents) to keep the home or vehicle
comfortable. Indoor pollen levels are increased by operating window or
attic fans. It is helpful to reduce outdoor activities during the
periods of high pollen counts. In general, limiting outdoor activities
on sunny, windy days with low humidity is advisable. Outdoor activities
may be tolerated following a rain.
A shower or bath following outdoor activity removes pollen from the hair
and skin and avoids contamination of bedding. In highly sensitive
patients whose symptoms are triggered by very low pollen levels,
effective allergen avoidance may require an absolute avoidance of
outdoor activity.
Some of the above measures may be impracticable, therefore, if you
suffer from the symptoms of Mountain Cedar allergy, you should contact
your physician for a precise diagnosis and appropriate treatment.
© 2008 Kim Hovanky. All Rights Reserved.
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