Bronchitis overview

Bronchitis Main page
Patient Information
Overview
Causes
Classification Acute bronchitis Chronic bronchitis
Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]

Overview

Bronchitis is an inflammation of the bronchi (medium and large size airways). Acute bronchitis is a self-limiting disease caused by viruses or bacteria. Chronic bronchitis is a disease by definition and is part of chronic obstructive pulmonary disease (COPD) which is defined as productive cough for at least three months in two consecutive years. Inflammatory response of the bronchial epithelium to infections or irritants that involve the medium and large size airways results in thickening of the bronchial and tracheal mucosa. Hallmark features of chronic bronchitis pathophysiology include: hyperplasia and hypertrophy of the goblet cells of the airway, resulting in an increase in secretion of mucus which contributes to the airway obstruction. Microscopically there is infiltration of the airway walls with inflammatory cells, particularly neutrophils. Inflammation is followed by scarring and remodeling that thickens the walls resulting in narrowing of the small airway. Further progression leads to metaplasia and fibrosis of the lower airway. The consequence of these changes is a limitation of airflow. Acute bronchitis affects young children and old people. Its overall incidence is approximately 5% in the U.S. There is no racial or gender predilection for this disease.Although, Chronic bronchitis is common among geriatric patients. It occurs more commonly among Caucasian individuals compared to other races, but equally between males and females. Age, season of the year and the immunization status are the main determining risk factors for acquiring acute bronchitis. The most potent risk factor in the development of chronic bronchitis is cigarette smoking. Other risk factors are occupational pollutants, such as cadmium, silica, and air pollutants, and genetic factors, such as alpha 1 antitrypsin deficiency Acute bronchitis is a self limiting lower respiratory tract infection that usually presents with cough that lasts for up to 3 weeks. Chronic bronchitis usually gradually worsens over time and can result in death. The rate of deterioration varies between individuals and depends on the level of airflow obstruction. Prognosis is dependent on early recognition and smoking cessation, which improves the outcome significantly. Cigarette cessation, hand hygiene, vaccination and reduction in occupational exposure are the mainstays to decrease the severity and the risk of bronchitis.

Classification

Bronchitis is classified in to two major categorize based on symptom chronicity.

• Acute bronchitis
• Chronic bronchitis

Differential diagnosis

Organ System	Disease	Symptoms	Signs	Laboratory findings	Diagnostic modality	Management
Cardiac	HFpEF	Exertional dyspnea, reduced exercise tolerance, orthopnea, paroxysmal nocturnal dyspnea, edema	Elevated JVP, fine crackles, edema	Increased BNP	Echocardiography (normal EF)	Control of volume overload and hypertension, treatment of underlying condition (obesity, AF, coronary artery disease, anemia)
	HFrEF	Exertional dyspnea, reduced exercise tolerance, orthopnea, paroxysmal nocturnal dyspnea, edema	Elevated JVP, fine crackles, edema	Increased BNP	Echocardiography (reduced EF)	Diuretics, ACE inhibitors, ARBs, beta blockers, nitrates
	Pericardial disease	Exercise intolerance, dyspnea, fatigue	Elevated JVP, pericardial knock, kussmaul's sign, pulsus paradoxus	-	Echocardiography, ECG	Diuretics, pericardiectomy
	Hypertrophic cardiomyopathy	Dyspnea, chest pain, palpitation, lightheadedness	Systolic murmur	-	Echocardiography, ECG	Beta blockers, verapamil
	Valvular disease (MR, TR)	Edema, fatigue, exercise intolerance, dyspnea, lightheadedness	Cardiac murmur	-	Echocardiography, ECG	Valve repair or replacement, diuretics, beta blockers
Pulmonary	Chronic airway disease	Cough, dyspnea, chest pain, exercise intolerance	Tachypnea, respiratory distress, cyanosis, edema, rhonchi and crackles	Hypoxemia, hypercapnea, polycythemia,	PFT, chest imaging	Bronchodilators, corticosteroids, anticholinergics
	Interstitial lung diseaee	Exercise intolerance, cough	Crackles, clubbing, cyanosis	Hypoxemia	PFT, Chest imaging, lung biopsy	Corticosteroids, bronchodilators
	Pulmonary hypertension	Dyspnea, fatigue, chest pain, syncope, palpitation	Edema, clubbing, elevated JVP, TR murmur	Elevated BNP, elevated d-dimer	Echocardiography, cardiac cathaterization	Diuretics, calcium channel blockers, endothelin receptor antagonist, phosphodiesterase 5 inhibitor
	Sleep apnea	Snoring, somnolence, headache, fatigue, irritability	Tachypnea, hypertension, tachycardia	Hypoxemia, polycythemia	Polysomnography	Weight reduction, CPAP
	Asthma	Dry cough, dyspnea, wheezing	Wheezing, tachypnea	Hypoxemia	PFT	Bronchodilators, corticosteroids, anticholinergics
Others	Liver disease	Fatigue, edema, jaundice	Ascites, palmar erythema, gynecomastia	Increased AST and ALT, decreased albumin, increased Br	Liver function test, Liver biopsy	Diuretics, treatment of underlying disease
	Chronic kidney disease	Fatigue, anorexia, nausea, edema, decreased exercise tolerance	Edema, hypertension, crackles	Increased BUN and Cr	BUN, Cr	Control of blood pressure, anemia, dialysis, kidney transplant