Definition
A.Coughing is a mechanism that clears the airway of secretions and inhaled particles. The act of coughing has the potential to traumatize the upper airway (e.g., vocal cords). A chronic cough is one that lasts longer than 8 weeks.
B.Because coughing can be an effective behavior, psychological issues must be considered as a cause or effect of coughing.
Incidence
A.Data on the incidence of coughing is not available. However, most healthy people do not cough, and the main reason for coughing is airway clearance. A chronic cough is the most common presenting symptom in adults who seek medical treatment in an ambulatory setting.
Pathogenesis
A.Stimulation of mucosal neural receptors in the nasopharynx, ears, larynx, trachea, and bronchi can produce a cough, as can acute inflammation and/or irritation of the respiratory tract. Cough is a reflex response that is mediated by the medulla but is subject to voluntary control. There is clear evidence that vagal afferent nerves regulate involuntary coughing.
B.Pertussis (whooping cough) is caused by the bacterium Bordetella pertussis.
C.The pathogenic triad of chronic cough responsible for 92% to 100% of chronic coughs is as follows:
1.Upper airway cough syndrome (UACS), previously referred to as postnasal drip syndrome.
2.Asthma.
3.Gastroesophageal reflux disease (GERD).
Predisposing Factors
A.Pharyngeal irritants including postnasal drainage.
B.Foreign-body aspiration.
C.Tuberculosis (TB) (persons in prisons and nursing homes and immigrants from endemic areas of TB).
D.Psychogenic factors.
E.Mediastinal or pulmonary masses.
F.Congestive heart failure (CHF).
G.Cystic fibrosis (CF).
H.Congenital malformations.
I.Viral bronchitis.
J.Asthma (sole symptom in 28%).
K.Mycoplasma infection.
L.Upper airway cough syndrome, previously referred to as postnasal drip.
M.Chronic sinusitis.
N.Allergic rhinitis.
O.Environmental irritants.
P.GERD.
Q.Chronic bronchitis.
R.Pulmonary edema.
S.Medications, including angiotensinconverting enzyme (ACE) inhibitors.
T.Impacted cerumen and external otitis.
U.Nonasthmatic eosinophilic bronchitis (NAEB, 13%–33%).
V.Swallowing dysfunction in elderly.
Common Complaints
A.Common complaint is a cough that interferes with activities of daily living (ADL) and sleeping, leading to a decrease in a patient’s quality of life (QOL).
B.The pertussis cough is uncontrollable and violent. Following coughing, a whooping
sound follows with a deep breath.
Other Signs and Symptoms
A.Fatigue.
B.Rhinitis.
C.Epistaxis.
D.Tickle in throat.
E.Pharyngitis.
F.Night sweats.
G.Dyspnea.
H.Fever.
I.Sputum production.
J.Hoarseness.
Subjective Data
A.Elicit information about onset, duration, and course of the cough. Was onset recent or gradual? Does the cough occur at night? Nocturnal cough may be caused by chronic interstitial pulmonary edema and may signal left-sided heart failure. Cough caused by asthma is also worse at night. Morning cough with sputum suggests bronchitis.
B.Inquire about the cough’s characteristics. For example, is it productive, dry, bronchospastic, brassy, wheezy, strong, or weak? If it is productive, is it bloody or mucoid? What is the color, consistency, odor, and amount of sputum or mucus? Dry, irritative cough suggests viral respiratory infection. Severe or changing cough should be evaluated for bronchogenic carcinoma. Rusty-colored sputum suggests bacterial pneumonia. Green or very purulent sputum is due to degeneration of white cells. HIV cough also produces purulent sputum.
C.Inquire whether the cough is associated with eating and choking episodes. Wheezing or stridor with coughing may indicate a foreign body or aspiration.
D.Ask whether the cough is associated with postnasal drip, which produces a chronic cough, clear sputum, edematous nasal mucosa, and a cobblestoned
pharyngeal mucosa.
E.Find out if the cough is associated with heartburn or a sour taste in the mouth, indicating GERD.
F.Ask about precipitating factors, such as exercise, cold air, or laughing. Also ask about alleviating factors. Cough from asthma can be triggered or exacerbated by exposure to environmental irritants, allergens, cold, or exercise.
G.Ask about current and previous work. Is the patient exposed to occupational and environmental irritants, such as dust, fumes, or gases? If so, what are the type, level, and duration of exposures?
H.Ask about family history of respiratory illness, such as CF or asthma.
I.Is the patient a smoker? If so, how much does he or she smoke, and how long has he or she smoked? Are they interested in cessation? Is he or she exposed to secondhand smoke? How much of the day? Smoking is the main cause of chronic cough.
J.Find out the date of the patient’s last tuberculin skin test. Note recent exposure to TB.
K.Inquire about any exposure to the flu.
L.Does the patient have a history of heart problems?
M.Does the patient have a history of respiratory problems or other medical problems? Chronic bronchitis is a major cause of chronic cough and sputum production. Cough may also be an early sign of lung cancer; in late stages, cough occurs along with weight loss, anorexia, and dyspnea.
N.Review medications such as ACE inhibitors. Cough related to ACE inhibitors usually subsides within 2 weeks, but the median time is up to 26 days.
O.Weight loss or worsening dyspnea?
P.Exposure to TB. (Confined living conditions? Incarceration?)
Q.Ask about pain in back or bony skeleton.
R.Ask if previous screening for lung cancer (as appropriate) with low dose CT.
Physical Examination
A.Record temperature if indicated, blood pressure (BP), and weight. Compare previous changes in weight.
B.Inspect:
1.Observe general appearance for cyanosis, difficulty breathing, use of axillary muscles, and finger clubbing.
2.Examine ears, nose, and throat.
C.Auscultate: Auscultate heart and lungs.
D.Percuss:
1.Percuss sinus cavities and mastoid process.
2.Percuss chest and lungs for consolidation.
E.Palpate:
1.Palpate face for sinus tenderness.
2.Examine head and neck for lymph nodes, masses, and jugular vein distension (JVD).
Diagnostic Tests
Testing can be held to a minimum by careful review of history and physical exam.
A.White blood cell (WBC) if infection suspected.
B.HIV test if suspected.
C.Sputum for eosinophils, Gram stain, and/or culture.
D.Mantoux test if indicated.
E.Chest radiograph (CXR).
F.Pulmonary function testing/spirometry.
G.Methacholine challenge to rule out asthma.
H.Esophageal pH monitoring to rule out GERD.
I.CT with consideration of contrast scan if necessary (radiologist may need to determine).
Differential Diagnoses
A.Environmental irritants:
1.Cigarette, cigar, or pipe smoking.
2.Pollutants (wood smoke, smog, burning leaves, etc.).
3.Dust.
4.Lack of humidity.
5.Chemical exposure in home or workplace, including illicit substances.
B.Lower respiratory tract problems:
1.Lung cancer.
2.Asthma.
3.Chronic obstructive lung disease (includes bronchitis).
4.Interstitial lung disease.
5.CHF.
6.Pneumonitis.
7.Bronchiectasis.
8.Foreign body or aspiration.
9.Tracheal–esophageal fistula.
10.Pulmonary embolism.
11.Pulmonary edema.
12.Pneumonia.
C.Upper respiratory tract problems:
1.Chronic rhinitis.
2.Chronic sinusitis.
3.Disease of external auditory canal.
4.Pharyngitis.
D.Medication-induced cough from ACE inhibitors.
E.Extrinsic compression lesions:
1.Adenopathy.
2.Malignancy.
3.Aortic aneurysm.
F.Psychogenic factors.
G.Gastrointestinal problems such as reflux esophagitis.
H.Genetic problems such as CF.
Plan
A.General intervention: If sputum is purulent, obtain a sample for examination.
B.Patients with chronic obstructive pulmonary disease (COPD) and CF should be taught huffing as an adjunct to other methods of sputum clearance.
C. 
See Section III: Patient Teaching Guide Cough.
D.Pharmaceutical therapy:
1.The risk of cough suppressants outweighs the benefits of use.
2.Antibiotics should not be prescribed for coughs unless a bacterial infection is suspected.
3.Therapy depends on various acute inflammatory and chronic irritating processes and on cause of cough. Refer to applicable sections of this chapter, such as Asthma
and Tuberculosis,
and see section Gastroesophageal Reflux Disease
of Chapter 14.
4.Inhaled or oral antihistamines could be considered if cough is related to allergic rhinitis. Potential side effects versus benefits should be considered, especially in the elderly.
Follow-Up
A.The patient with a normal CXR and no risk factors for lung cancer (e.g., smoking or occupational exposure) can be followed expectantly without further testing.
B.In patients whose cough resolves after the cessation of ACE inhibitors, and for whom there is a compelling reason to treat with these agents, substitution with an angiotensin II receptor blocker (ARB) is recommended.
C.See applicable sections for specific diagnoses.
D.Pertussis vaccination booster should be administered to all adults according to Centers for Disease Control and Prevention (CDC) adult vaccine guidelines. Pertussis cases should be reported to the local health department.
Consultation/Referral
A.Consult a physician if symptoms persist after treatment. Reevaluate patient in 2 weeks if he or she is no better.
B.When a cough lasts more than 2 weeks without another apparent cause and it is accompanied by paroxysms of coughing, posttussive vomiting, and/or an inspiratory whooping sound, the diagnosis of a B. pertussis infection should be made unless another diagnosis is proven.
C.Patients whose condition remains undiagnosed after a workup and therapy may need referral to a cough specialist.
Individual Considerations
A.Pregnancy: Cough may be an early symptom of pulmonary edema. Watch intrapartum patients for signs of edema.
B.Adolescents: Dextromethorphan has been associated with abuse potential.
C.Geriatrics:
1.The risk of side effects from over-the-counter (OTC) cough suppressants should be discussed with the patient.
2.Elderly patients with dementia are generally unable to perform the forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) diagnostic tests. In the elderly with dementia, consider COPD in older adults who have any of the following factors. The greater the number of factors, the more likely COPD is present: