TABLE OF CONTENTS

I. Introduction
II. Common Causes of Chronic Cough
III. Less Common Causes of Chronic Cough
IV. Diagnostic and Therapeutic Approach

I. INTRODUCTION

We understand that dealing with a chronic cough can be an annoying and frustrating experience. Fortunately, we have different treatments that may help alleviate your cough. Listed below are some information that can help you better understand your chronic cough.

We define cough to be either:

• An “Acute” cough lasting less than 2-3 weeks (most likely due to a common cold); or
• A “Chronic” cough lasting for 3 weeks or more

II. COMMON CAUSES OF CHRONIC COUGH

In patients with a normal chest xray, 95% of chronic cough is caused by one or more of the following three problems: postnasal drip, asthma and gastroesophageal reflux disease.

Postnasal Drip (PND)

PND is the most common cause of cough. It may be caused by a recent cold, within the past 6 weeks. Other symptoms associated with PND may include:

(1) a feeling of mucous dripping into the throat

(2) frequent throat clearing

(3) nasal congestion or discharge

(4) hoarseness.

PND is usually treated with an oral antihistamine and a nasal spray to decrease mucous production in the back of the nose. It is important to understand that newer, nonsedating antihistamines (such as fexofenadine or Allegra and loratadine or Claritin) seldom relieve cough in patients with PND since they do not dry secretions. These newer antihistamines may be useful for patients with true allergic PND, but that is a less common cause of chronic cough.

Nasal steroid sprays rarely are effective by themselves in treating chronic cough from PND. The sinuses need to be pretreated with Kaiser's saline flush kit (flushing mucus out of the sinuses before applying nasal steroids) or else the nasal steroid sprays merely coat the mucus and do not work.

Asthma

Asthma is the second most common cause of chronic cough. In some patients, cough is the only symptom of asthma (“cough variant asthma”). Other patients may have wheezing, shortness of breath, and a feeling of tightness in the chest. Adult onset asthma is fairly common and can come and go with colds, changes in the weather, or high pollen seasons.

Cough due to asthma usually goes away when the asthma is effectively treated. Asthma is usually treated with one or more inhaled medicines.

Additional information on Asthma

Gastroesophageal Reflux Disease (GERD)

Stomach contents can travel back up the swallowing tube and irritate the airway opening or even get into the bronchial tubes, causing cough, chronic bronchitis and/or asthma

GERD may be difficult to diagnose. Many patients with GERD-related cough do not have typical “indigestion” symptoms such as heartburn, sour taste, or regurgitation.

Treatment of GERD includes dietary restrictions (giving up caffeine, chocolate, alcohol and spicy foods), elevating the head of the bed, and the use of medicines to decrease the production of stomach acid. These therapies may take several weeks to have a full effect on GERD-related cough.

Additional information on GERD

III. LESS COMMON CAUSES OF CHRONIC COUGH

Chronic Bronchitis

Chronic bronchitis is especially common in smokers because tobacco smoke irritates the airways and damages the body’s normal ways of clearing mucus. Quitting smoking is the only effective treatment for chronic bronchitis in a smoker.

Because smokers often "expect to cough," they may not seek medical attention for a cough that persists. Smokers should contact their physician if they notice a change in their coughing pattern, or any sign of blood in their sputum.

Additional information related to Chronic Bronchitis

Bronchiectasis

Bronchiectasis is an uncommon disease of the airways in which some of the bronchial passages are widened and bacteria can grow in these areas more easily. This condition is seen in patients with cystic fibrosis and may be seen in a much milder form in patients who have a history of multiple pneumonias or childhood respiratory infections. Bronchiectasis is usually characterized by chronic cough with periods of increased mucus production. It is diagnosed by plain chest xray or CT scan.

Lung Cancer

Lung cancer is an uncommon cause of chronic cough in nonsmokers. A new cough in a smoker or ex-smoker should be evaluated within the first month by chest xray.

Additional Information on Lung Cancer

ACE Inhibitor-Induced Cough

Angiotensin-converting enzyme (ACE) inhibitors are blood pressure-lowering drugs that cause chronic cough as a side effect in up to 10% of patients. The cough is typically dry and hacking. Stopping the medication causes the cough to improve or resolve within a month.

Habit Cough

Frequent throat clearing may be done out of habit or in the setting of anxiety or personal stress.. Medical treatment is not necessary.

Interstitial Lung Disease

Inflammation or scarring of the lungs is an uncommon cause of cough that may be seen in the setting of some medications (such as Amiodarone or Macrodantin) or rheumatologic illnesses (such as Rheumatoid Arthritis or Scleroderma). Often the underlying reason for the inflammation is unknown (“idiopathic”.) This condition is diagnosed by chest xray and/or CT scan.

IV. DIAGNOSTIC AND THERAPEUTIC APPROACH

The initial evaluation for a cough lasting longer than 4 weeks should include a chest x-ray. Occasionally, a pulmonary function test looking for evidence of asthma may also be ordered. If your symptoms point toward a certain source (for example, post nasal drip and frequent throat clearing), then this will be treated first to see if the cough goes away.

Unfortunately, there are few specific tests to evaluate cough. Therefore, the diagnostic and therapeutic approach involves trying out different treatments to see which works best. In about 2/3 of patients, there are at least two problems (for example, post nasal drip and mild asthma) contributing to cough. As a result, the cough may improve somewhat with treatment addressing one problem, but may need additional treatment for the other problem(s).

The only way to eliminate a cough is to treat the cause - that is why cough syrups and cough drops don't work. While cough is an annoying and frustrating symptom, it rarely represents a serious medical problem (with a normal chest x-ray). In most cases, the cough is treatable once the underlying problem is understood and treated. If a cough is diagnosed as due to GERD, and the treatment does not relieve the GERD, this does not mean the diagnosis was incorrect - it means a different therapy needs to be tried to treat the GERD. Patience on the part of both patient and physician is sometimes required to successfully figure out the causes of a longstanding cough.

2005, The Permanente Medical Group. Department of Pulmonology. Material adapted with permission from the ACCP’s Patient Education Guide to Chronic Cough on chestnet.org/education