Acute Bronchitis

Fred F. Ferri, M.D.

Basic Information

Definition

Acute bronchitis is a self-limited inflammation of trachea and bronchi.

Synonyms

Chest cold

ICD-10CM CODES
J20.9	Acute bronchitis, unspecified

Epidemiology & Demographics

•

Highest incidence in smokers, older adults, and young children and during winter months.
•

In the U.S. there are nearly 30 million ambulatory visits annually for cough, leading to more than 12 million diagnoses of “bronchitis.”
•

Acute lower respiratory tract infection is the most common condition treated in primary care.

Physical Findings & Clinical Presentation

•

In most cases, acute bronchitis begins with signs and symptoms typical of the common cold syndrome (nasal congestion, sore throat), followed shortly by the onset of cough
•

Cough, usually worse in the morning, often productive; mainly caused by transient bronchial hyperresponsiveness
•

Low-grade fever
•

Substernal discomfort worsened by coughing
•

Postnasal drip, pharyngeal injection
•

Rhonchi that may clear after cough, occasional wheezing
•

Various host factors (age, immune status, smoking, underlying medical conditions) can influence illness severity and clinical presentation
•

In mild cases, the illness lasts only 7 to 10 days, whereas in others, cough may persist for up to 3 weeks or longer

Etiology

•

Viral infections are the leading cause of bronchitis (rhinovirus, influenza virus, adenovirus, respiratory syncytial virus)
•

Atypical organisms (Mycoplasma, Chlamydia pneumoniae)
•

Bacterial infections (Bordetella pertussis, Haemophilus influenzae, Moraxella, Streptococcus pneumoniae)

•

Table 1 summarizes viral and bacterial causes of acute bronchitis

TABLE1 Viral and Bacterial Causes of Acute BronchitisFrom Bennett JE, Dolin R, Blaser MJ: Mandell, Douglas, and Bennett’s principles and practice of infectious diseases, ed 8, Philadelphia, 2015, Saunders.

Pathogen	Seasonality	Comments
Influenza viruses	Winter	Local epidemics last 6-8 wk during which clinical illness of cough and fever has high predictive value; laboratory diagnosis readily available; early neuraminidase inhibitor therapy effective
Rhinoviruses	Fall and spring	Most frequent cause of common cold syndrome; immunity is serotype specific
Coronaviruses	Winter to spring	Cause common cold syndrome; newer strains are difficult to culture and require RT-PCR for diagnosis
Adenoviruses	Year round, winter epidemics	High attack rates in closed populations such as persons living in military barracks or college dormitories; serotype-specific immunity
Respiratory syncytial virus (RSV)	Late fall to early spring	Attack rates approach 75% in neonates, 3%-5% in adults; associated with wheezing in all age groups; rapid antigen test accurate in children but requires culture or RT-PCR to diagnose in adults
Human metapneumovirus (hMPV)	Winter to early spring	Associated with wheezing in adults and in infants; difficult to isolate in tissue culture and often requires RT-PCR
Parainfluenza viruses	Fall to winter	Similar to RSV and hMPV, parainfluenza viruses primarily pediatric pathogens but can cause severe acute disease in some adults
Measles virus	Year round	Can cause respiratory disease in malnourished children; illness causes transient immune suppression
Mycoplasma pneumoniae	Year round, fall outbreaks	Long incubation period (10-21 days) results in staggered epidemic pattern in families; nonproductive persistent cough typical; diagnosed by IgM serology; treated with macrolide, quinolone, or tetracycline antibiotics
Chlamydia pneumoniae	Year round	Associated with sinusitis; diagnosis by RT-PCR not readily available
Bordetella pertussis	Year round	Severe illness in nonimmunized children; illness milder in partially immune adults; can be associated with prolonged cough; adults often reservoir for epidemics; early therapy with antibiotics can reduce spread
RT-PCR, Reverse-transcriptase polymerase chain reaction.

Diagnosis

Differential Diagnosis

•

Pneumonia
•

Asthma
•

Sinusitis
•

Bronchiolitis
•

Aspiration
•

Cystic fibrosis
•

Pharyngitis
•

Cough secondary to medications
•

Neoplasm (elderly patients)
•

Influenza
•

Allergic aspergillosis
•

Gastroesophageal reflux disease
•

Congestive heart failure (in elderly patients)
•

Bronchogenic neoplasm

Workup

Seldom necessary (e.g., to rule out pneumonia, neoplasm)

Laboratory Tests

Laboratory tests are generally not necessary.

Imaging Studies

Chest x-ray is usually reserved for patients with suspected pneumonia, influenza, or underlying chronic obstructive pulmonary disease (COPD) and no improvement with therapy.

Treatment

Nonpharmacologic Therapy

•

Avoidance of tobacco and other pulmonary irritants
•

Increased fluid intake
•

Use of vaporizer to increase room humidity

Acute General Rx

•

Therapy is generally symptomatic and directed at relief of cough and wheezing.
•

Inhaled bronchodilators (e.g., albuterol, metaproterenol) PRN for 1 to 2 wk in patients with wheezing or troublesome cough. Inhaled albuterol has been proven effective in reducing the duration of cough in adults with uncomplicated acute bronchitis.
•

Cough suppression with dextromethorphan and guaifenesin is commonly recommended; addition of codeine for cough suppression if cough is severe and is significantly interrupting patient’s sleep pattern.
•

Use of antibiotics (TMP-SMX, amoxicillin, doxycycline, cefuroxime) for acute bronchitis is generally not indicated; should be considered only in patients with concomitant COPD and purulent sputum or in patients with suspected pertussis. In the few cases of acute bronchitis caused by B. pertussis or atypical bacteria such as C. pneumoniae or Mycoplasma pneumoniae, early use of macrolide antibiotics is reasonable.
•

Antibiotics are overused in patients with acute bronchitis (70% to 90% of office visits for acute bronchitis result in treatment with antibiotics); this practice pattern is contributing to increases in resistant organisms.
•

Trials have shown that there are no significant differences in patients receiving antibiotics compared with those receiving placebo in overall clinical improvements or limitations in work or other activities. There was a significant increase in adverse effects in the antibiotic group, particularly gastrointestinal symptoms.¹

Chronic Rx

Avoidance of tobacco and other pulmonary irritants

Disposition

•

Complete recovery within 7 to 10 days in most patients.
•

Patients should be informed to expect to have a cough for 10 to 14 days after the visit.

Referral

For pulmonary function testing only in patients with recurrent bronchitis and suspected underlying pulmonary disease.

Pearls & Considerations

Comments

•

Patients are more likely to receive prescriptions for antibiotics from mid- or late-career physicians with high patient volumes and from physicians who were trained outside of Canada or the U.S.² Intervention studies reveal that patient and physician education are effective in reducing the use of antibiotic therapy. No offer or delayed offer of antibiotics for acute uncomplicated lower respiratory tract infection is acceptable, is associated with little difference in symptom resolution, and is likely to reduce antibiotic use and beliefs in the effectiveness of antibiotics.
•

It is helpful to refer to acute bronchitis as a “chest cold.” Patients should be informed that antibiotics are probably not going to be beneficial and may result in significant side effects.

Ferri – Acute Bronchitis