TABLE 21-6.

Differentiating among Causes of Cough

	Peak Age	Nature of Cough	Cough Dominant Feature?	Anticipated/Associated Findings
Infections of the respiratory tract
Viral laryngotracheitis	>5 years	Brassy, painful	Yes	Hoarse, raspy voice; viral URI complexa
Viral laryngotracheitis/laryngotracheobronchitis	4 months–3 years	Barking, brassy	Codominant with stridor	Stridor, hoarseness, viral URI complexa
Mycoplasmal tracheobronchitis	Adolescent	Hacking, paroxysmal, painful	Yes	Prodromal, fever, headache, myalgia; then gradual worsening cough
Pertussis	Infancy, adolescence	Sudden paroxysm of explosive machine-gun bursts (15–30 per breath)	Yes	Bulging, watering eyes during paroxysm, posttussive emesis; skin and conjunctival hemorrhages; afebrile, without lower respiratory tract symptoms or symptoms between paroxysms
Chlamydia trachomatis pneumonia	1–3 months	Staccato, dry (single cough per breath)	Yes	History can include conjunctivitis; afebrile, tachypnea, rales
Bronchiolitis	4 months–2 years	High-pitched or grunt	No	Wheezing, rhinorrhea, respiratory distress; ± fever
Pneumonia (bacterial or viral)	Any	Wet, productive or nonproductive	Codominant with respiratory distress	Tachypnea, rales, respiratory distress; fever
Pleurodynia	Any	Inspiratory hitch; expiratory grunt	Codominant with chest pain	Chest pain; costochondral tenderness
Sinusitis	Any	Irritative; occurs in day and worsens at night	Sometimes	Mucopurulent rhinorrhea, postnasal discharge; facial pain, swelling, or tenderness; headache; ± fever
Tracheoesophagitis (fungal or viral)	Any	Irritative	No	Odynophagia or dysphagia; immune-compromised host; hoarseness; oropharyngeal lesions
Cystic fibrosis	<2 years; any	Wet, productive; paroxysmal, hacking	Sometimes	Poor growth; persistent and recurrent sinusitis, pneumonia; digital clubbing
Protracted bacterial bronchitis	Any, mean 8–9 years	Wet, productive; >8 weeks	Yes	Bronchoscopy; neutrophils, bacteria, cytokines; response to antibiotic
Other conditions
Purulent pericarditis	Any	Grunt	Sometimes	Fever, toxicity, respiratory distress/dyspnea; displaced point of maximum impulse; muffled heart sounds
Myocarditis	Any	Grunt	Sometimes	Fatigue, dyspnea, tachypnea; ± fever
Congestive heart failure	Any	Grunt, wet, or brassy	Sometimes	Fatigue, dyspnea, sweating, tachycardia, tachypnea; ± fever; distended neck veins, liver
Noninfectious airway abnormalities
Gastroesophageal reflux	6 weeks–6 months	High-pitched, dry	Codominant with other symptoms	Stridor, choking, gagging, irritability, arching (Sandifer syndrome) ± regurgitation, pneumonia
Reactive airway, asthma	6 months–adolescence	Irritative dry, repetitive (not paroxysmal); night especially	Sometimes	Atopic, precipitants, seasonal; ± wheezing; response to β-agonist
Congenital vascular rings, pulmonary sling	Infancy	Brassy	No	Stridor; onset of symptoms in first month of life
Compression on airway or glossopharyngeal or phrenic nerve	Any	Irritative, dry	Sometimes initially	Can be positional (tumors, other masses), associated with other neuropathies, stridor, changes in phonation
Habit cough	Adolescence	Vibratory, low-pitched, honking; disappears with sleep	Yes, sole feature	“La belle indifference”; family dynamics and other somatization

^aViral upper respiratory tract infection (URI) complex consists of fever, rhinorrhea, sore throat, conjunctivitis, exanthem, enanthem.