Chronic Cough

Common causes of chronic cough include asthma, allergic rhinitis, sinus problems,esophageal reflux, medications eg ACE inhibitors, and whooping cough. In rare cases, inhalation of foreign objects into the lungs (usually in children) can also cause chronic cough. It is important to see a doctor when a chronic cough is present. The following are common causes of chronic coughing.

• Cigarette smoking - the most common cause of chronic cough.
• Asthma - a disease of the airways that result in difficulty breathing or wheezing. Some asthma sufferers have chronic cough as their only symptom. Some may even have normal lung functions tests. This is often referred to as cough-variant asthma. Asthmatic symptoms can be aggravated by cold air, exposure to air pollutants, pollen, smoke, or perfumes.
• Gastroesophageal reflux disease (GERD) refers to acid reflux, or backward flow, of stomach acid and other contents into the esophagus. This can result in spasms of the airways that in turn can cause shortness of breath and coughing. In some instances, acid reflux can be so severe that substances can be inhaled (aspirated) into the lungs and cause similar symptoms as well as damage to lung tissue. In some individuals, no sensation of heartburn is felt and their only symptom may be chronic cough.
• Sinus problems and postnasal drip also causes chronic cough due to the backflow of mucus down the back of the throat. This condition can be difficult to detect. Sometimes a CT scan of the sinuses is necessary for diagnosis. Affected individuals often complain of a "tickle in their throat" and frequent throat clearing.
• Infections such as bronchitis or pneumonia can cause acute cough or a chronic cough. These infections can be caused by viruses, bacteria, or fungi. For asthmatics, viral upper respiratory infections often result in a prolonged cough even after the infection has cleared. 
• Bronchitis is also a common cause of a chronic cough and is often associated with coughing up blood (hemoptysis).
• Whooping cough (pertussis) is an acute, highly contagious respiratory infection caused by the bacterium Bordetella pertussis. It can cause violent, rapid, constant coughing and be fatal in young children. Whooping cough commonly affects infants and young children, but can be prevented by immunization with the pertussis vaccine. In adults, whooping cough can be a cause of chronic cough.
• Chronic cough in children is uncommon. Foreign materials obstructing the airways of the lungs, asthma, and allergies are the usual suspects and patients need to be evaluated by a pediatrician.
• Certain medications, notably ACE inhibitors (enalapril [Vasotec], captopril [Capoten] etc.) used in treating high blood pressure can cause chronic cough.
• Less common causes of chronic cough include allergies, tumors, sarcoidosis, congestive heart failure, and/or other lung diseases such as chronic obstructive pulmonary disease (COPD) or emphysema. Lung diseases also can cause coughing up blood.

If chronic cough persists, it is important to be evaluated by a doctor. 

What Are The Different Types Of Chronic Coughs?

There are several different types of chronic (or persistent) cough.

• A persistent dry cough is a cough that does not produce any mucus, irritating to the lungs and throat, and may be a sign of a viral infection or sinus problems.
• A chronic wet cough is a cough that produces mucus (sputum), and depending on the color, may indicate a bacterial infection or fluid in the lungs (congestive heart failure).
• A stress cough is a reflexive spasm of the airways caused when you are under stress. It usually produces no mucus and is not generally related to infections.
• A 'barking' cough is usually found in children, and may be associated with croup or other viral illness. The harsh, barking sound of a croup cough is caused by a swollen windpipe (trachea).
• A cough that causes a 'whooping' sound after the cough may be indicative of a serious infection and should be evaluated by a doctor. Whooping cough (pertussis) is a highly contagious respiratory disease that can be deadly for babies under 1 year of age.

What Kinds Of Doctors Treat Chronic Coughs?

Family practitioners in the primary care sector or internist will be able to diagnose the cause of your chronic cough. 

Patients suffering from constant cough may be referred to different specialists if the underlying cause of the chronic cough is severe or cannot be found.

A pulmonologist is a lung specialist who treats diseases of the airways. An allergist is an allergy specialist who may treat chronic cough due to allergies. Gastroenterologists specialize in diseases of the digestive tract and can treat chronic cough due to conditions such as gastroesophageal reflux disorder (GERD). Cardiologists specialize in diseases of the heart and circulatory system and may treat persistent cough that can be a secondary symptom of heart disease.

How Is Chronic Cough Treated?

The treatment of chronic cough is directed at the underlying cause. 

In severe cases of chronic cough a healthcare professional may prescribe codeine or other similar narcotic medications - these act as cough suppressants.

The following are examples of treatments for chronic cough caused by medications, conditions, or diseases.

• Asthma: Inhaled bronchodilators and inhaled steroids are given to decrease inflammation of the airways and reduce wheezing. This reduces chronic cough. In some cases, short-term oral steroids are prescribed to relieve chronic cough.
• Gastroesophageal reflux disease (GERD): Treatment for chronic cough caused by GERD includes avoiding foods that increase reflux, avoiding lying down after meals, elevating the head while sleeping, and taking medication such as famotidine (Pepcid), cimetidine (Tagamet), ranitidine (Zantac) omeprazole (Prilosec, Prilosec OTC), lansoprazole (Prevacid, Prevacid 24-Hour), rabeprazole (Aciphex), pantoprazole (Protonix), esomeprazole (Nexium) to decrease stomach acidity.
• Sinus problems and postnasal drip: Use of decongestants such as pseudoephedrine (Sudafed) or antihistamines such as diphenhydramine (Benadryl) may improve symptoms of post nasal drip, which causes a persistent, nagging, cough. Inhaled nasal steroids are also very effective in treating allergic rhinitis (hay fever), a common cause of cough. Additionally, other nasal inhalers like ipratropium bromide (Atrovent) can relieve post nasal drip. Antibiotics may be prescribed if the cause is determined to be sinusitis.
• Infections: Bacterial pneumonia and bronchitis are typically treated with antibiotics such as cephalosporins, azithromycin (Zithromax), and other antibiotics. If the pneumonia is close to the chest wall, inflammation of the surface of the lung can cause pain. This is known as pleurisy and pain relievers (analgesics) can be helpful. Cough suppressants are used with caution in these situations because clearing the lung of the infected mucus by coughing helps clear the infection and suppressing the cough reflex is counter-productive. Suppressants, however, are given more for symptomatic relief.. Note though that most forms of bronchitis in adults are caused by viral infections. Therefore, treatment is much the same as that of the common cold, inclusive of rest, fluids, pain relievers, and humidification. Expectorant cough medicines containing guaifenesin can be helpful in alleviating discomfort. Sometimes, it is hard to differentiate a viral from bacterial bronchitis, and antibiotics will be prescribed by the doctors as a precaution. In some cases, asthmatics can produce green mucus that looks infected. Your doctor send the sputum sample to a lab to be  examined.
• Medications: Hypertensive patients with chronic cough that are on blood pressure medicines called ACE inhibitors (angiotensin converting enzyme), for example, enalapril (Vasotec), captopril (Capoten), lisinopril (Zestril, Prinivil), etc. should talk to their doctor about switching medications. Patients should not stop taking medicine on their own because a marked elevation in blood pressure can result from discontinuation. A newer generation of ACE inhibitor like medicines called ARBs (angiotensin receptor blockers, for example, valsartan [Diovan], losartan [Cozaar], etc.) can be alternatives as they are less likely to cause chronic coughing. There are also other options available for treatment of blood pressure.

Are There Home Remedies For Chronic Cough?

Certain Home Remedies will be of benefit. These include:

• Staying hydrated. Fluids will thin secretions.
• Gargle with warm saltwater to help cleanse the throat and rid it of mucus.
• Elevate your head with extra pillows at night to ease a chronic dry cough.
• Inhale steam in a shower or use a humidifier to relieve dry cough.
• Cough drops may soothe an irritated throat.
• Do not smoke or use tobacco products.
• Avoid inhaled irritants such as smoke, dust, or other pollutants.
• Honey often can be an effective treatment for a persistent cough. Add honey to hot tea, or even grape juice.
• Ginger, prepared as a tea, is often used to help reduce symptoms of chronic cough and clear the nasal passages.
• Other herbs such as eucalyptus or mint are often used to relieve cough symptoms.

Can Chronic Cough Be Prevented?

• Don't smoke, as smoking is the most common cause of chronic cough.
• Talk to your physician about managing your asthma, postnasal drip, or GERD to avoid chronic cough symptoms.
• Stay away from others known to be sick with bronchitis or pneumonia.
• Eat fruit. Research suggests that diets high in fruit fiber and flavonoids may prevent chronic productive cough.
• Make sure you and your child gets the whooping cough (pertussis) vaccine.

About The Author

Dr Lau Tzun Hon is a resident housecall doctor at CMY Medical. He received his MBBS (Hons) from Sydney University in 2001 and has served in the both private and government restructured hospitals prior to commencing his practice in Home Care.

While in the Government Restructured Hospitals, Dr Lau served primarily in the Department of Accident & Emergency Medicine and Anaesthesia. Upon entering the Private sector, Dr Lau worked in both public and private A&E departments before venturing into Home Care.

Over the years, he has developed a strong passion to maintain and  enhance the quality of life for patients under his care.  A strong believer that healthcare does not need to be financially straining, Dr Lau often delivers more value beyond expectations.