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Topic of the Month: March 2006: Spring allergies and cough
In this month's topic you will learn:
- Causes of cough
- Treatment for cough and spring allergies
- When to see an asthma/allergy specialist
- How to prevent allergy symptoms
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Do you have a lingering cough that won't go away? Cough is a common symptom of spring allergies such as allergic rhinitis (hayfever). In fact, cough is the most common respiratory symptom for which patients seek medical attention.
Spring allergies are triggered by substances called allergens. Allergens are often common, usually harmless substances such as pollen, mold spores, animal dander, dust, foods, insect venoms and medications.
Cough is a way that the body protects itself from these allergens. It helps by removing mucus, fluids, and infections from the airways.
Coughing does not always mean there is a problem, however coughing at night after going to sleep is almost always abnormal and needs medical attention.
Causes of cough
In children, cough is divided into acute cough (usually lasting one to two weeks) and chronic cough (lasting greater than four weeks).
- Acute cough - Most children with brief periods of coughing are coughing because of viral upper respiratory tract infections. Many different viruses cause these infections in children. Healthy preschool children in day care can have up to six to eight viral respiratory infections with cough every year. This acute cough is usually due to postnasal drip and direct airway irritation by the virus. Postnasal drip is a condition in which mucus drips slowly from the nose and sinuses to the back of the throat. Medications may or may not be necessary or helpful. It is best to check with your doctor.
 Nasal and sinus disease causing cough - Postnasal drip due to rhinitis (inflammation in the nasal passages) or sinusitis (inflammation in the sinus cavities) is another common cause of cough that can become chronic. Usually, other symptoms such as nasal congestion and runny nose are present, but sometimes the only symptom noticed is the cough. Allergic rhinitis, either seasonal or year-round, is often the cause, and tests for allergies may be necessary. Sinus infections can persist for weeks to months causing cough, sometimes with minimal nasal symptoms. Occasionally, your doctor may advice you to do a sinus X-ray or limited CT scan of the sinuses.- Stomach and esophageal causes of cough - In some children, the cause of chronic cough is due to problems with the stomach and esophagus (food tube). Most commonly, this is due to gastroesophageal reflux disease (GERD). This is often associated with a feeling of heartburn. But young children often don't complain of heartburn because they may not know it is abnormal or may not be able to describe the feeling. In some children, heartburn does not seem to occur even with GERD. Other children may develop a hoarse voice and/or choking as a symptom of GERD. This may need to be investigated by your doctor which includes a trial of medicines for GERD. X-rays and other tests to look at the stomach and esophagus or measure stomach acid refluxing into the esophagus may also be needed. In young infants, reflux and swallowing problems are a common cause of persistent cough, particularly when it occurs after eating.
Other causes of cough include:
- Post-viral cough - Children without asthma, allergies or sinusitis can have a cough after viral respiratory infections lasting for weeks. There is no specific therapy for this cough and it does eventually resolve. It is often due to increased sensitivity at the cough trigger points and is suspected when the cough does not respond well to asthma medications. Cough suppressant medications can be tried but they are not always helpful.
- Inhaled foreign body - Although small foreign bodies, such as a piece of a plastic toy or part of a peanut, hot dog or a hard candy can be accidentally inhaled at any age, it most commonly occurs in boys, ages two to four years. The foreign body may or may not appear on an x-ray. It can cause a cough to persist for many weeks to months until it is discovered.
- "Habit" cough - This is a persistent cough that has no physical cause. It occurs most commonly in children, adolescents and young adults. It occasionally persists after a simple viral respiratory infection. The cough typically is dry and repetitive or is a "honking" cough that usually worries parents and teachers much more than the child. Habit cough is absent at night after the child goes to sleep.
- Irritant cough - Exposure to environmental tobacco smoke and other pollutants (smoke and exhaust from wood burning, air pollution and exhaust from vehicles) is associated with increased cough in healthy children and may worsen the cough associated with asthma or rhinitis. These substances should be avoided, particularly in children with asthma or rhinitis.
 Treatment
Often, simple daytime cough after viral respiratory infections requires no specific treatment, particularly if it resolves in one or two weeks.
The primary treatment for chronic cough should be aimed at the underlying cause-asthma, GERD, rhinitis or sinusitis. Treating cough symptoms with mucus thinning agents such as guaiafenesin has limited benefit in most patients. Cough suppressing medications such as over-the-counter medications that contain dextromethorphan are also of limited value, but can be tried. Stronger cough suppressing agents such as codeine-containing medications are more effective, but have more side effects and should only be used for short periods of time.
Patients should contact a doctor if a cough changes in character, trial therapy shows no signs of reducing the cough, you begin to cough up blood and/or the cough interferes with the activities of daily living or sleep.
When to see an allergy/asthma specialist
The AAAAI's How the Allergist/Immunologist Can Help: Consultation and Referral Guidelines Citing the Evidence provide information to assist patients and health care professionals in determining when a patient may need consultation or ongoing specialty care by the allergist/immunologist. Patients should see an allergist/immunologist if they:
- Have a cough that lasts 3-8 weeks or more.
- Have a cough that coexists with asthma.
- Have coexisting chronic cough and nasal symptoms.
- Have a chronic cough and tobacco use or exposure.
Preventing allergy symptoms
If the right precautions are taken there is no reason why even the worst allergy sufferers have to tolerate allergy symptoms. The AAAAI recommends the following tips to help lessen allergy symptoms this allergy season:
- Do a thorough spring cleaning - windows, book shelves and air conditioning vents collected dust and mold throughout the winter that can provoke allergy symptoms
- Postpone outdoor activities until later in the morning. Pollens are usually emitted between the hours from 5 am - 10 am
- Know your local pollen count by visiting the National Allergy Bureau Web site
- If possible use air conditioning instead of having windows opened
- When traveling in a car have the windows up and the air conditioning on
- Stay indoors on hot, dry and windy days
- Don't hang your laundry out to dry. Allergens will collect on them
- Do not mow the lawn or rake the leaves without a filter mask
- Wash bedding weekly in hot water
- Shower and wash your hair every night before going to bed
- Remove visible mold with non-toxic cleaning products
- Beware of high mold spore counts after a heavy rain or in the evening
Additional Resources
This topic was reviewed on 3/1/2006 by Stuart Friedman, MD, FAAAAI, Patients & Consumers Web Editor
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