By Anne Stephenson, BA, MD, FRCPC
This article appeared in the AAIA
newsletter in March 2000. If you'd like to get a newsletter regularly,
join us with an AAIA membership.
Patients with asthma develop difficulty
breathing because of irritated airways that result in shortness
of breath, wheezing, and cough. A variety of factors, such as
allergies, cold air, exercise, and respiratory infections, can
worsen this condition. Another potential trigger for asthma symptoms
is acid reflux from the stomach or heartburn.
Although many people have symptoms of heartburn, including burning
sensation behind the breast bone, acid taste in the mouth, cough,
and sometimes nausea, others do not experience any symptoms, so-called
"silent" reflux. The only symptom may be that their
asthma is difficult to control with the usual medications. Since
between 30 and 90% of adult asthmatics have reflux, this is an
important condition to consider in difficult-to-control asthmatics.
Why does reflux aggravate asthma?
There are two possible reasons by which reflux can narrow
the airways and worsen asthma. The first is that acid from the
stomach can track up the esophagus (feeding tube), particularly
when you lie down. Small amounts of acidic fluid can trickle down
into the airways causing them to narrow and thereby create shortness
of breath and wheezing. Alternatively, acid can reach the lower
part of the esophagus and stimulate nerve endings. This can cause
the smooth muscle in the airways to contract, which narrows the
breathing tubes. The patient perceives this as shortness of breath.
How is reflux-induced asthma diagnosed?
Often the diagnosis is made based on a clinical history and
improvement of symptoms with therapy. Symptoms of reflux-induced
asthma are listed in Table 1. Remember, it is possible that the
only symptom may be difficulty in controlling your asthma on your
usual medications.
Table 1: Typical Symptoms of Reflux-induced
Asthma
- Asthma symptoms are worse
after eating high fat meal, coffee, chocolate or alcohol
- Wheezing, shortness of
breath, cough while experiencing heartburn symptoms like
burning, acid taste in the mouth
- Persistent cough, particularly
if worse when lying down.
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Specialized tests are available,
such as 24-hour esophageal pH monitoring, which measures the acid
content in the esophagus. The patient documents asthma symptoms
which are then matched with the esophageal acid events to confirm
the diagnosis. It can also be used to monitor the effectiveness
of reflux therapy.
What is the treatment?
Standard therapy for asthma, such as inhaled corticosteroids and
bronchodilators should be optimized. If symptoms of asthma persist,
despite optimal therapy, reflux should be considered as a possible
aggravating factor.
There are many non-medical therapies to help improve reflux including:
- weight loss if overweight
- eating a low fat diet
- elevating the head of the bed
- avoiding certain foods which are
known to worsen reflux such as coffee, alcohol, and caffeine
- avoid large meals late at night
In addition, there are safe and effective
medications which can decrease the amount of acid in the stomach
and control symptoms of both reflux and asthma. The two major
groups of medications include proton-pump inhibitors (PPI), such
as omeprazole, and H-2 blockers such as ranitidine. PPI are more
effective at decreasing acid and their side effects are minimal.
A final option for the treatment of reflux is surgery, but this
is appropriate only in severe cases that have failed all alternative
therapies.
Dr. Anne Stephenson is an Internal Medicine specialist who
is completing her respiratory fellowship at UBC, Division of Respiratory
Medicine, Vancouver General Hospital. She has interests in asthma,
interstitial lung disease and pulmonary research.
Allergy/Asthma Information Association,
Box 100, Toronto, Ontario M9W 5K9
Phone (416) 679-9521 or 1-800-611-7011 Fax: (416) 679-9524
Web site: http://www.aaia.ca
E-mail: national@aaia.ca
