Coughing is so prevalent — especially during the winter months — that most people dismiss it as a minor ailment that will go away on its own.
Recent development: A highly contagious type of cough that often is accompanied by classic cold symptoms, such as sneezing and a runny nose, is on the rise among American adults. Reported cases of pertussis, commonly known as whooping cough, recently reached a 40-year high in the US — and the disease now strikes up to 600,000 Americans each year.
SHOULD YOU SEE A DOCTOR?
A cough that accompanies a cold usually goes away within a matter of days. But sometimes a cough can linger for weeks or months. If a cough lasts more than two months, it is considered chronic and should be evaluated by a physician. Regardless of how long it has lasted, any cough that seriously disturbs your sleep, work or family or social life should be treated by a doctor. If violent enough, a cough can cause sore muscles — and even break ribs or precipitate bouts of fainting or vomiting.
Important: A cough that occurs with certain other symptoms may signal a potentially serious illness. For example, if you have a high fever and/or cough up dark-colored phlegm or blood, it may indicate pneumonia… chest pain and shortness of breath could mean a collapsed lung… and blood-streaked sputum and wheezing could indicate lung cancer. These conditions require immediate medical care.
To treat a nagging cough that occurs without the additional symptoms described above, the underlying cause must be identified.
If you exclude smoking and medication side effects — blood pressure–lowering drugs known as angiotensin-converting enzyme (ACE) inhibitors, such as enalapril (Vasotec), often trigger coughing — more than 90% of all chronic coughs are caused by three conditions (in order of prevalence)…
• Upper-airway cough syndrome is a new term for what used to be called postnasal drip. The syndrome includes coughing due not only to postnasal drip (mucus accumulation in the back of the nose or throat), but also resulting from other effects of nose, sinus or throat irritation or inflammation.
Best treatment options: Older antihistamines, such as chlorpheniramine (Chlor-Trimeton), and decongestants, such as pseudoephedrine (the active ingredient in Sudafed), are the only medications shown in studies to provide much relief — especially when taken in combination. (Pseudoephedrine is available “behind-the-counter” at drugstores.) Newer antihistamines, such as loratadine (Claritin) and fexofenadine (Allegra), are easier to take because they don’t make you as drowsy but don’t seem to work as well against cough.
There’s little evidence that expectorant or suppressive cough syrups do much — they don’t get at the cause of the cough. But a potent cough suppressant, such as one with codeine or hydrocodone, can offer temporary relief when a severe cough prevents sleep. For allergic rhinitis (due to such conditions as hay fever or an allergy to animal dander), inhaled steroids are the best choice, while antibiotics treat chronic sinusitis.
• Asthma is the next most common cause of cough. If accompanied by wheezing and shortness of breath, asthma is easy to diagnose. But much of the time, cough is the only symptom. This condition is known as cough-variant asthma.
Best treatment options: Cough-variant asthma usually responds to the same treatments as traditional asthma — inhaled steroids, plus other drugs, such as bronchodilators, if needed. Some of the newest asthma medications — leukotriene receptor antagonists, such as montelukast (Singulair) — are particularly effective for asthmatic cough.
Important: Once cough-variant asthma goes away, it’s tempting to stop treatment. But experts now agree that this type of asthma may affect the lungs much the way traditional asthma does, causing chronic inflammation and thickening of the airway wall that could lead to irreversible obstruction. For this reason, it’s safest to continue treatment as instructed by your physician.
New development: Nonasthmatic eosinophilic bronchitis (NAEB) recently has been recognized as a cause of chronic cough. The prevalence of this condition in the US is unknown, but European studies have found that 13% of people with chronic cough have NAEB. Like asthmatic cough, NAEB responds well to inhaled steroids.
• Gastroesophageal reflux disease (GERD) is one of the most common causes of chronic cough in the US. GERD is associated with heartburn but also can cause a cough — with or without heartburn. Coughing results when stomach contents back up into the esophagus, stimulating cough receptors. If acid reaches the voice box (larynx), coughing may occur with other upper respiratory symptoms, such as hoarseness.
Best treatment options: Cough caused by GERD generally improves with standard lifestyle changes (such as avoiding alcohol, caffeine and chocolate… and not eating within two hours of bedtime) and acid-suppressing medication prescribed for ordinary reflux. In some cases, two drugs — a proton pump inhibitor, such as omeprazole (Prilosec), and an H2 blocker, such as ranitidine (Zantac) — may be needed to eliminate cough-causing GERD.
In some people, bile and other nonacidic contents of the stomach are to blame, and drugs, such as metoclopramide (Reglan), are needed to strengthen the sphincter valve at the base of the esophagus and hasten stomach emptying.
A type of laparoscopic surgery (which involves wrapping part of the upper stomach around the sphincter to strengthen it) is helpful if drugs don’t work, but may only reduce — not cure — the cough.
• Pertussis, which was first identified in the early 1900s, causes a nagging cough that often lingers for weeks or even months. The disease was largely eradicated in the US with widespread use of a childhood vaccine, but pertussis is now re-emerging as immunity from the illness has begun to weaken in some people during adulthood.
The Centers for Disease Control and Prevention now recommends a booster pertussis vaccine, which has been approved for adults ages 19 to 64. Because the vaccine is acellular (made from bacterial fragments, rather than the whole organism), it is unlikely to cause arm soreness, fever or other adverse reactions.
If treated during the two weeks of acute infection, pertussis responds well to antibiotics, such as erythromycin (E-Mycin). But because early symptoms resemble those of the common cold — and there’s often nothing distinctive about the cough (adults are unlikely to display the loud and forceful “whoop” from which the disease gets its name) — pertussis often remains undiagnosed until the cough has become severe. At this point, antibiotics are less effective, because the infection is too advanced. The infection resolves with time.
Caution: Pertussis is extremely contagious — one person can infect most or all of the people in his/her household. If a member of your household has pertussis, you should be seen by a physician as a precaution.
WHY WE COUGH
Coughing is a vital reflex that helps clear mucus, airborne chemicals and other substances from the airways, which extend from the throat to the lungs. Foreign substances trigger coughing by irritating receptors (nerve endings that line the airways). Coughing usually results from respiratory infections, allergies or smoking, but lesser-known causes (described in this article) also may be to blame.