Acute Bronchitis

Symptoms are a nonproductive or mildly productive cough accompanied or preceded by URI symptoms, usually by > 5 days. Subjective dyspnea results from chest pain or tightness with breathing, not from hypoxia.

Signs are often absent but may include scattered rhonchi and wheezing. Sputum may be clear, purulent, or occasionally contain streaks of blood. Sputum characteristics do not correspond with a particular etiology (ie, viral vs bacterial). Mild fever may be present, but high or prolonged fever is unusual and suggests influenza, pneumonia, or COVID-19.

On resolution, cough is the last symptom to subside and often takes 2 to 3 weeks or even longer to do so.

Diagnosis is based on clinical presentation. Microbiologic testing is usually unnecessary. However, patients with signs or symptoms of COVID-19 in the current pandemic should be tested for SARS-CoV-2. Diagnostic testing for influenza and pertussis should also be considered if there is high clinical suspicion based on exposure and/or clinical features. Patients who complain of dyspnea should have pulse oximetry to rule out hypoxemia. Chest x-ray is done if findings suggest serious illness or pneumonia Community-Acquired Pneumonia Community-acquired pneumonia is defined as pneumonia that is acquired outside the hospital. The most commonly identified pathogens are Streptococcus pneumoniae, Haemophilus influenzae... read more (eg, ill appearance, mental status change, high fever, tachypnea, hypoxemia, crackles, signs of consolidation or pleural effusion). Older patients are the occasional exception, as they may have pneumonia without fever and auscultatory findings, presenting instead with altered mental status and tachypnea.

Sputum Gram stain and culture usually have no role. Nasopharyngeal samples can be tested for influenza and pertussis Diagnosis Pertussis is a highly communicable disease occurring mostly in children and adolescents and caused by the gram-negative bacterium Bordetella pertussis. Symptoms are initially those of... read more if these disorders are clinically suspected (eg, for pertussis, persistent and paroxysmal cough after 10 to 14 days of illness, only sometimes with the characteristic whoop and/or retching, exposure to a confirmed case). Viral panel testing is not usually recommended because results do not affect treatment.

Cough resolves within 2 weeks in 75% of patients. Patients with persistent cough should undergo a chest x-ray. The decision to evaluate for noninfectious causes, including asthma, postnasal drip, and gastroesophageal reflux disease Gastroesophageal Reflux Disease (GERD) Incompetence of the lower esophageal sphincter allows reflux of gastric contents into the esophagus, causing burning pain. Prolonged reflux may lead to esophagitis, stricture, and rarely metaplasia... read more , can usually be made on the basis of the clinical presentation. Differentiation of cough-variant asthma Asthma Asthma is a disease of diffuse airway inflammation caused by a variety of triggering stimuli resulting in partially or completely reversible bronchoconstriction. Symptoms and signs include dyspnea... read more may require pulmonary function testing.

Acute bronchitis in otherwise healthy patients is a major cause of antibiotic overuse. Nearly all patients require only symptomatic treatment, such as acetaminophen and hydration. Evidence supporting efficacy of routine use of other symptomatic treatments, such as antitussives, mucolytics, and bronchodilators, is weak. Antitussives Treatment should be considered only if the cough is distressing or interfering with sleep. Patients with wheezing may benefit from an inhaled beta2-agonist (eg, albuterol) for a few days. Broader use of beta2-agonists is not recommended because adverse effects such as tremor, nervousness, and shaking are common.

Though some studies have shown modest symptomatic benefits with antibiotic use in acute bronchitis, the low incidence of bacterial causation, self-limiting nature of acute bronchitis, and the risk of adverse effects and antibiotic resistance Antibiotic Resistance Antibacterial drugs are derived from bacteria or molds or are synthesized de novo. Technically, “antibiotic” refers only to antimicrobials derived from bacteria or molds but is often (including... read more argue against widespread antibiotic use. Oral antibiotics are typically not used except in patients with pertussis Pertussis Pertussis is a highly communicable disease occurring mostly in children and adolescents and caused by the gram-negative bacterium Bordetella pertussis. Symptoms are initially those of... read more or during known outbreaks of bacterial infection (mycoplasma, chlamydia). A macrolide such as azithromycin 500 mg orally once, then 250 mg orally once a day for 4 days or clarithromycin 500 mg orally twice a day for 7 days is the preferred choice.