Chronic Cough

Description of Medical Condition

Chronic cough is defined as cough of >3 weeks duration. Patients present for fear of underlying pathology (eg, cancer), annoyance, self-consciousness, hoarseness. Patients with stress urinary incontinence may find cough particularly troubling. COPD and smoking-related cough are most common etiologies at the primary care level.

System(s) affected: Pulmonary, Gastrointestinal

Genetics: N/A

Incidence/Prevalence in USA: Prevalence of 14-23% in nonsmokers

Predominant age: All age groups

Predominant sex: Male = Female

Medical Symptoms and Signs of Disease

Variable and related to the underlying cause
Usually nonproductive cough with no other signs or symptoms. May persist up to 6 weeks after resolution of viral illness.
Possible signs and symptoms of allergic diathesis, rhinitis, sinusitis, GERD, CHF, connective tissue disorders

What Causes Disease?

Often multiple etiologies, but most are related to bronchial irritation. Up to 42% of patients have more than one cause. Most frequent (account for 94% of cases)

Postnasal drip (PND)
Asthma
Gastroesophageal reflex disease (GERD)
Chronic bronchitis

Other causes:

Aberrant innominate artery OACE inhibitor therapy
Aspiration
Bronchiectasis
Congestive heart failure
Cystic fibrosis
Eosinophilic lung disease
External auditory canal irritation
Laryngeal cancer
Laryngotracheomalacia
Lung neoplasm (e.g.,, bronchogenic carcinoma)
Pertussis
Post-viral bronchial hyperresponsiveness
Psychogenic (habit cough)
Restrictive lung disease
TB, atypical mycobacterium, and other chronic lung infections

Risk Factors

Smoking
Stress (particularly school stress in children)

Diagnosis of Disease

Differential Diagnosis

N/A

Drugs that may alter lab results: N/A

Disorders that may alter lab results: N/A

Pathological Findings

Specific to underlying etiology

Special Tests

Sputum for eosinophils and cytology
Purified protein derivative (PPD) skin testing
Pulmonary function testing with beta-2 agonist
Sweat chloride testing

Imaging

Chest x-ray
Chest CT if needed
Upper Gl series
Sinus series or sinus CT

Diagnostic Procedures

History and physical
- Age of the patient, presence of associated signs/ symptoms, medical history, medication (ACE inhibitor), environmental exposures, smoking history may make some causes more likely
- Absence of additional signs/symptoms of a particular condition not necessarily helpful (eg, 75% of GERD patients have no other signs or symptoms)
- Character of cough is rarely helpful
24 hour pH probe
Rarely bronchoscopy
Extensive testing only if indicated by the history and physical. Simple testing (chest x-ray, sinus studies) followed by empiric therapy directed at likely underlying etiology.

Treatment (Medical Therapy)

Appropriate Health Care

Outpatient

General Measures

Directed at most likely etiology
Eliminate smoking and ACE inhibitors
Often empiric treatment of PND and GERD
Attempt maximal therapy for single most likely cause for several weeks, then search for coexistent etiologies

Surgical Measures

Fundoplication is often effective for cough secondary to refractory GERD
Cough secondary to chronic sinusitis may improve post-surgically

Activity

GERD patients may benefit from elevation of head of the bed and elimination of pre-bedtime meals

Diet

GERD patients may benefit from avoidance of EtOH, caffeine, nicotine, citrus, fatty foods

Patient Education

Reassurance that vast majority of causes are not life threatening, and they can be managed effectively
Counsel — that several weeks-months may be required for significant reduction or elimination of cough
Prepare for the possibility of multiple diagnostic tests and therapeutic regimens as treatment is often empiric

Medications (Drugs, Medicines)

Drug(s) of Choice

Antitussives
- Dextromethorphan (Delsym) 30mg bid, age > 6 years
- Narcotics: codeine 15-30 mg q6h, hydrocodone (Vicodin) 5mg q6h
Other treatments (antacids, bronchodilators, antibiotics, etc.) directed at etiology of cough

Contraindications: N/A

Precautions: N/A

Significant possible interactions: N/A

Alternative Drugs

N/A

Patient Monitoring

Frequent followup to assess effectiveness of treatment and addition of other medications as needed
Consider stepwise withdrawal of medications after resolution of cough

Prevention / Avoidance

N/A

Possible Complications

Tussive syncope
Tussive headache
Stress urinary incontinence
Abdominal and intercostal muscle strain
Inguinal hernia
Pneumothorax
Medication side-effects

Expected Course / Prognosis

Most patients (>90%) can be effectively diagnosed and treated with a systematic approach
Cough from any cause may take weeks to months until resolution, and resolution is highly dependent on efficacy of treatment directed at underlying etiology

Miscellaneous

Associated Conditions

N/A

Age-Related Factors

Pediatric: Habit cough more likely in school-aged children

Geriatric: N/A

Pregnancy

N/A

International Classification of Diseases

786.2 Cough

306.1 Physiological malfunction arising from mental factors, respiratory

491.0 Simple chronic bronchitis

493.90 Asthma, unspecified

Other Notes

Algorithms for diagnosis and treatment can be found in references

Abbreviations

GERD = Gastroesophageal reflux disease PPI = Proton pump inhibitor MAI = mycobacterium avium-intracellulare PND = Postnasal drip