Description

• Chronic cough is defined as a cough that persists for >8 weeks in adults.
• Subacute cough describes a cough lasting 3–8 weeks.
• In children, chronic cough is often defined as a cough of >4 weeks in duration.
• Patients present because of fear of the causative illness (e.g., cancer), as well as annoyance, self-consciousness, and hoarseness.
• Patients with stress urinary incontinence may find cough particularly troubling.
• At the primary care level, chronic obstructive pulmonary disease (COPD) and smoking-related cough are common causes of chronic cough.
• System(s) affected: Gastrointestinal; Pulmonary

Epidemiology

• Predominant age: All age groups
• Predominant sex: Male = Female

Incidence
Recurrent cough has been reported at 3–40% by various population estimates.

Prevalence
Chronic cough is one of the most common reasons for primary care visits.

Risk Factors

Although various conditions may contribute to chronic cough, the main causes include smoking and pulmonary diseases.

Pathophysiology

Varies with findings and disorders implicated

Etiology

• Often multiple etiologies, but most are related to bronchial irritation. Most frequent etiologies (account for >90% of cases) in nonsmokers include:
  • Upper airway cough syndrome (UACS) (formerly referred to as postnasal drip syndrome) and other upper airway abnormalities, including allergic and vasomotor rhinitis syndromes
  • Asthma
  • Nonasthmatic eosinophilic bronchitis (NAEB)
  • Gastroesophageal reflux disease (GERD)
• Other causes:
  • Chronic smoking or exposure to smoke or pollutants
  • Aspiration
  • Bronchiectasis
  • ACE inhibitors
  • Infections (e.g., pertussis, tuberculosis)
  • Cystic fibrosis
  • Sleep apnea
  • Restrictive lung diseases (e.g., chronic interstitial lung disease)
  • Neoplasms: Bronchogenic or laryngeal cancer, other
  • Psychogenic (habit cough)
• Cough reflex hypersensitivity or cough hypersensitivity syndrome are new labels attempting to define a syndrome of cough with characteristic trigger symptoms not adequately explained by other medical conditions (1).

Commonly Associated Conditions

Patients with UACS, asthma, and GERD may present with chronic cough as the only symptom and not the usual symptoms associated with the diagnoses.