Cough - what you need to know

When a patient presents with a cough, it may not be just a trivial complaint. Our guide offers helpful clues to coughs that can be self-managed and those which need to be taken more seriously

One of the most common symptoms that brings people to see a healthcare professional is a cough. They may have had it for a day or several weeks but it can be troublesome for people as it may prevent them or their partner from sleeping, may make them vomit and can put a strain on their chest muscles as well as being socially disabling.

Coughing is a symptom not a disease and the aim of this article is to look at possible underlying causes for the cough, the importance of taking a good history, when to refer and any medication or remedy that might help to alleviate the cough.

Coughing can be divided into the acute cough, lasting less than 3 weeks and usually self-limiting, resolving cough (3-8 weeks), and a chronic, persistent cough lasting more than 8 weeks. See box 1 for brief details on the chronic cough.

CAUSES OF ACUTE COUGH¹

Coughing is often a conscious reaction to something in the throat such as dust particles or food going down the wrong way, and although this can be uncomfortable for a short time, the reaction usually passes quickly and does not require any intervention or self-care. If the person is gasping for air they need emergency assistance and an ambulance should be called and oxygen given.

A viral cold or influenza is probably the most common reason for a cough. The virus makes the nasal passages produce copious amounts of mucus, which runs out of the nose but can also give a choking feeling in the throat, especially when lying down at night, which stimulates the cough reflex. After the first few days of a cold the mucus tends to thicken making coughing even more likely and this could continue for two weeks or more and is usually described as a post-viral cough. See below for general self care treatment of viral infections.

Acute bronchitis is a common infection of the bronchi, the main symptom being a cough. It is usually a viral infection, although it can be bacterial. Other symptoms can include fever, headache, cold symptoms and aches and pains, which typically peak after 2-3 days, then gradually clear. It may take 2-3 weeks for the cough to disappear because of the inflammation in the airways. The infection will normally clear itself with self-care as below.

Bacterial infections such as sinusitis, when the nose produces green or yellow mucus and the person has a high temperature and headache, can develop after a viral infection with a cough remaining for a while afterwards. Self care is usually advocated using over the counter (OTC) analgesics and decongestants but antibiotics may sometimes be necessary to clear the infection.

Post nasal drip caused by viral or bacterial infections or allergies (allergic rhinitis) leads to continual clearing of the throat and an irritating cough. Nasal sprays can be bought OTC or prescribed which can relieve these symptoms.

Croup is a common viral infection in babies and children in the winter months. It is characterised by a barking cough, fever and runny nose and often develops suddenly when an apparently well child wakes in the night with the croupy cough and trouble with its breathing. Another common symptom of croup is inspiratory stridor, which is a loud, high-pitched, harsh noise made when breathing in. It can be confused with wheezing.

These symptoms are often worse at night or when the child is agitated. Cool air seems to help the symptoms. Although most croup symptoms are mild, some children do develop more severe breathing difficulties and parents should be advised, if that is the case, to take the child to A&E immediately. Home treatment advice should include giving antipyretics such as ibuprofen (not if the child has asthma) and paracetamol, keeping the child calm in a cool place and offering plenty of fluids.

Whooping cough, caused by the bacterium Bordetella pertussis, is characterised by intense bouts of coughing with a 'whoop' sound with each sharp intake of breath after coughing (although this may not always occur in infants and young children). The early symptoms of whooping cough are similar to those of the viral cold and can last for one to two weeks, before becoming more severe with the 'whooping' cough. Each bout of coughing usually lasts between one and two minutes, but several bouts may occur in quick succession and last several minutes. The number of coughing bouts experienced each day varies, but is usually between 12 and 15. This cough usually lasts at least two weeks, but can last longer up to three months or more, even after treatment. This is because the cough continues even after the Bordetella pertussis bacterium has been cleared from the body. As most children in the UK have been vaccinated against whooping cough it is rare to see a child with a bad 'whooping' cough. Infants younger than three months may not make the 'whoop' sound after coughing, but they may start gagging or gasping, and may temporarily stop breathing. It is possible for whooping cough to cause sudden unexpected death in infants and other complications such as pneumonia so again parents need to be advised to take the infant to A&E if there are any signs of breathing problems.

MORE SEVERE INFECTIONS OR MEDICAL CONDITIONS

Severe acute respiratory syndrome (SARS)² a serious form of pneumonia, is caused by a virus isolated in 2003. Infection with the SARS virus results in acute respiratory distress and sometimes death. Coughing spreads the virus by droplets and within 6 weeks of its discovery, it had infected thousands of people around the world. It is a dramatic example of how quickly world travel can spread a disease! The hallmark symptoms for SARS are fever greater than 38.0^0 C (100.4^0 F) and cough, difficulty breathing, or other respiratory symptoms. Anyone with these symptoms who has been travelling should be referred to A&E for isolation and treatment.

Pulmonary embolism is caused by a 'wandering' blood clot, usually from a deep vein thrombosis (DVT). Having major surgery or sitting for long periods of time without moving, for example on a long train, car or plane journey can cause a DVT. If a blood clot arrives in the lungs and blocks one of the blood vessels then coughing may be one of the symptoms. Questioning at the assessment will find out if this might be the possible cause of a cough, in which case refer immediately to the GP.

CAUSES OF CHRONIC COUGH

Asthma is caused by a trigger in an atopic person. Triggers such as pet dander, pollen, feathers or house dust mite, irritate the airways causing the muscles around the walls of the airways to tighten so becoming narrower, and inflamed. The lining of the airways swells and mucus builds up making breathing difficult. A wheeze and cough are usually the first signs of asthma but sometimes there is only a cough. If there is a history of asthma then asking about compliance with inhalers and looking at inhaler technique is a useful first step in finding a cause for the cough. Many parents do not realise that their child's cough can be due to the worsening of its asthma. Refer to the asthma specialist nurse or GP for review.

Smoking damages the cilia lining the trachea. These small hair-like projections help to move irritants upwards towards the oropharynx so that they can be swallowed. Phlegm is an irritant but because of the damage to the cilia the only way it can be removed is through coughing. Many smokers develop an early morning cough to clear the phlegm produced overnight.

Chronic Obstructive Pulmonary Disease develops in long-term smokers, who may then have a chronic cough. A spirometry test will need to be done to exclude this. Give advice on smoking cessation, refer to your local stop smoking clinic and the GP for further review.

A symptom of heart failure can be coughing, with white or pink blood-tinged mucus, when fluid builds up in the lungs. If this is suspected the patient should be immediately referred to a doctor.

In 6 to 10% of patients with chronic cough, Gastro-oesophageal-reflux-disease (GORD) is the underlying cause. A certain amount of gastro-oeasophageal reflux is normal but if it is prolonged or excessive it may cause irritation of the oesophagus which can be very painful. If this cause is suspected then referral to a GP is necessary and the patient may be sent for an endoscopy. OTC antacids do help the pain but should not be taken continuously. Antacids may impair the absorption of some drugs, such as ACE inhibitors, tetracyclines and some antimalarials, if taken at the same time.³

ACE inhibitor cough is an irritating dry cough associated with the use of ACE Inhibitors for hypertension.⁴ It is possible that a lower dose might resolve the cough but it may be necessary to withdraw the drug if the cough continues. Switching to another ACE inhibitor is unlikely to help so referral to the GP is necessary for another class of drug to be prescribed.⁵

Work-related cough. There are several occupations that may cause a chronic cough or occupational asthma such as welding, baking, mushroom farming and building (removal of asbestos) but Health and Safety regulations these days should prevent problems arising. However, it is always worth asking about a person's employment, as they may not bother to wear the safety equipment provided. Many of these diseases are reportable to the Health and Safety Executive under the Reporting of Injuries, Diseases and Dangerous Occurrences Regulations (RIDDOR) 1995.⁶

Tuberculosis (TB) is a bacterial infection, spread through inhaling tiny droplets of saliva from the coughs or sneezes of an infected person. TB mainly affects the lungs. However, the infection can spread to many parts of the body, including the bones and nervous system. Typical symptoms of TB include:

• persistent cough
• weight loss
• night sweats

If there is a history of TB in the patient or their family or they have been in close contact with someone who has proven TB then the patient should be referred to the GP for investigations and chest X-ray.

THE IMPORTANT ASSESSMENT

When a patient presents with a cough, although it may seem trivial, it is wise to take a few minutes to ask some questions, the answers to which may give a clue to the cause of the cough.

• How long have you had the cough?
• What OTC medication have you tried?
• Do you have any history of a recent viral cold or flu, asthma, heart problems or indigestion?
• When does the cough occur, night or early morning, on exertion, after meals or in cold air?
• Any shortness of breath or wheezing?
• Have you coughed up any blood?
• What is your work? Do you have any pets or birds?
• Are you on any medication, including drugs for heart problems, high blood pressure or asthma?
• Have you ever been given inhalers, if so when do you use them?
• Have you been on holiday recently, in a plane or on a long train/car journey?
• Are you a smoker? If so, for how long?
• Do you use recreational drugs?

MANAGEMENT OF A COUGH

The British Thoracic Society has published guidelines on the management of cough in adults and children that give a more detailed look at this subject than can be given here (see Useful Resources). However, once an assessment has been done and the healthcare professional has found no reason to suspect a serious underlying cause then general management of the symptoms by self-care should be recommended, as follows:

• Reduction of fever by giving regular paracetamol or, if not asthmatic, ibuprofen according to the dosage on the packet
• Rest and plenty of fluids
• Warm honey and lemon drinks (not if the person is diabetic)
• Nutritious diet including fruit and vegetables
• Advise people to call NHS Direct on 0845 4647 for further advice
• Infants and young children can always be seen by a healthcare professional if parents are worried.

Cold and cough remedies can be bought at pharmacies so advise patients to ask a pharmacist for suitable OTC medications. These remedies will have little impact on any infection, but they may be useful for certain symptoms. For example, a decongestant nose spray may help to clear a blocked nose. See Box 2 for the latest advice on OTC cough and cold remedies for children.

Remember to advise that cold and cough remedies often contain several ingredients, especially paracetamol, so the patient needs to watch that they do not exceed the maximum safe dose. Some may cause drowsiness. This may be welcome at bedtime but not if driving. Someone with diabetes needs to look for sugar-free medications

RED FLAG SYMPTOMS

• Breathlessness and/or respiratory distress
• High temperature, not brought down by regular antipyretics
• Other distressing symptoms such as pallor, floppiness and disabling tiredness
• Length of time the person has had the cough
• Family history/ own history of allergies, asthma, TB, medication
• Coughing up blood

CONCLUSION

Coughing can be the symptom of a simple viral cold or a more serious disease so healthcare professionals need to make a short assessment of the presenting patient's symptoms before advising general self-care. This article has described the most common causes of coughing but some further study of the causes would enable the healthcare professional to have confidence in knowing what red flag symptoms to look out for and advise the patient about.

REFERENCES

1. Dicpinigaitis PV, Colice GL, Goolsby MJ et al. Acute cough: a diagnostic and therapeutic challenge. Cough 2009;5:11

2. WHO. Severe Acute Respiratory Syndeom (SARS). www.who.int.csr/sars/en

3. British National Formulary 61, March 2011 www.bnf.org.uk

4. Lalloo UG, Barnes Pj, Chung KF. Pathophysiology and clinical presentation of cough. J Allergy Clin Immunol 1996;98:S91-S96

5. Dicpinigaitis PV. Aniotensin-converting enzyme inhibitor-induced cough: ACCP evidence-based clinical practice guidelines. Chest 2006;126(Suppl 1):S169-73

6. Health and Safety Executive. Reporting of injuries, diseases and dangerous occurrences regulations (RIDDOR). www.hse.gov.uk/riddor/guidance.htm

7. Patient.co.uk Chronic cough in adults. http://www.patient.co.uk/doctor/Chronic-Cough.htm )

8. Medicines and Healthcare Products Regulatory Agency. Children's over-the-counter cough and cold remedies: new advice http://www.mhra.gov.uk/Safetyinformation/Safetywarningsalertsandrecalls/Safetywarningsandmessagesformedicines/CON038908