Self-limited inflammation of the large airways, almost always viral.
Also known as: acute bronchitis, viral bronchitis, chest cold
Overview
Self-limited inflammation of the trachea and large bronchi, predominantly viral in etiology, characterized by acute cough lasting up to 3 weeks, with or without sputum production, in patients without chronic lung disease.
Epidemiology
One of the most common reasons for ambulatory visits in the US (~5% of adults annually). Peak incidence in fall and winter. Antibiotic overprescription is a major stewardship concern — ~70% of cases historically received antibiotics despite minimal benefit.
Try two board-style Acute Bronchitis questions
Real questions from the FirstPassPA bank, with the full explanation. Pick an answer — no signup, no email.
Question 1PulmonaryEasy
A 34-year-old previously healthy woman presents with a 6-day history of cough productive of clear-to-yellow sputum, preceded by 2 days of sore throat and rhinorrhea. She denies fever, dyspnea, or chest pain. She has no smoking history and no recent sick contacts with pneumonia. Temperature is 37.2°C, HR 78, RR 16, SpO2 98% on room air. Lung exam reveals scattered wheezes and rhonchi that clear with cough; no focal crackles, no egophony. Chest x-ray shows no infiltrate. Which of the following is the most likely diagnosis?
AAcute exacerbation of asthma
BUpper airway cough syndrome
CAcute bronchitis
DPertussis
Reveal answer & full explanation
Correct answer: C — Acute bronchitis
AAcute exacerbation of asthma
BUpper airway cough syndrome
CAcute bronchitis✓
DPertussis
Why Acute bronchitis is correct
Acute bronchitis is a self-limited inflammation of the large airways, almost always viral (influenza, RSV, rhinovirus, coronavirus, adenovirus).
Hallmark: cough lasting up to 3 weeks, often productive, frequently preceded by upper respiratory symptoms (sore throat, rhinorrhea), in a patient without fever, tachypnea, hypoxia, or focal lung findings — as here.
A normal chest x-ray excludes pneumonia.
Why the others are wrong
Acute exacerbation of asthma — Features recurrent episodic wheeze with reversible obstruction and usually atopy or prior episodes; not a single post-viral cough illness in a previously healthy patient (confused-with reactive airway disease).
Upper airway cough syndrome — Postnasal drip produces weeks of throat clearing and a nonproductive cough with cobblestoned posterior pharynx, not a 6-day sputum-producing illness with wheezes and rhonchi that clear with cough (anchoring on the antecedent rhinorrhea).
Pertussis — Presents with paroxysmal coughing fits, post-tussive emesis, and inspiratory whoop after a catarrhal phase, lasting weeks to months; not this brief 6-day illness (premature closure).
Additional high-yield points
Acute bronchitis is treated supportively; antibiotics do not shorten duration and are not indicated unless pertussis or bacterial superinfection is suspected.
Question 2PulmonaryEasy
A 39-year-old woman has 4 days of cough, rhinorrhea, sore throat, and low-grade fever. Lung examination is clear, oxygen saturation is 98%, and chest radiograph is normal. Which of the following is the most likely diagnosis?
AAcute bacterial rhinosinusitis
BAcute viral bronchitis (self-limited)
CPertussis in the catarrhal stage
DCommunity-acquired lobar pneumonia
Reveal answer & full explanation
Correct answer: B — Acute viral bronchitis (self-limited)
AAcute bacterial rhinosinusitis
BAcute viral bronchitis (self-limited)✓
CPertussis in the catarrhal stage
DCommunity-acquired lobar pneumonia
Why Acute viral bronchitis (self-limited) is correct
Acute bronchitis is overwhelmingly viral and follows upper-respiratory symptoms with a self-limited cough.
Clear lungs, normal oxygen saturation, and a normal chest film argue against any parenchymal or vascular process.
A cough lasting days to a few weeks without consolidation is the board signature of acute bronchitis.
Why the others are wrong
Community-acquired lobar pneumonia — Anchoring on cough plus fever: pneumonia produces focal crackles, hypoxemia, or a radiographic infiltrate, all absent here.
Pertussis in the catarrhal stage — Early pertussis is genuinely coryzal, but it is far less common than viral bronchitis and declares itself over the next 1 to 2 weeks with paroxysmal coughing fits and post-tussive emesis.
Acute bacterial rhinosinusitis — Bacterial sinusitis requires symptoms persisting beyond 10 days, severe fever with purulent discharge, or double worsening; 4 days of coryza with a cough is still a viral course.
🔒 Free preview limit reached
Keep reading — start your free trial
You've read your 2 free diagnosis previews. Create your free account to unlock the full Acute Bronchitis outline — plus all 514 diagnoses, 6,500+ board-style questions, flashcards, and an AI tutor. Your 7-day free trial includes everything, and there's no credit card required.
Viral infection of bronchial epithelium → mucosal inflammation, edema, hypersecretion of mucus, bronchial hyperresponsiveness, and sloughing of cells → cough that can persist for 1-3 weeks after acute infection resolves due to lingering airway inflammation. Common pathogens: influenza A and B, RSV, rhinovirus, coronavirus (including SARS-CoV-2), adenovirus, parainfluenza, metapneumovirus. Bacterial causes (<10%): Bordetella pertussis, Mycoplasma pneumoniae, Chlamydophila pneumoniae.
Clinical presentation
Symptoms
Cough — initially dry, often becoming productive of clear or purulent sputum (PURULENT SPUTUM ALONE DOES NOT INDICATE BACTERIAL INFECTION)
Mild dyspnea, wheeze, chest discomfort with coughing
Often preceded by URI symptoms: rhinorrhea, sore throat, mild fever (low-grade)
Cough typically resolves within 1-3 weeks; postinfectious cough can last 6-8 weeks
Signs / physical exam
Generally normal exam; possible rhonchi/wheeze that clear with coughing
Low-grade fever or afebrile
Normal SpO2 and respiratory rate
Absence of focal consolidation, dullness, egophony (would suggest pneumonia)
ACE inhibitor cough — Dry cough developing after ACEi start; resolves on discontinuation (may take 4 weeks)
Diagnostic workup
Labs
Generally NONE needed in immunocompetent ambulatory patients with classic presentation
Procalcitonin and CRP not routinely indicated but can support antibiotic stewardship
Targeted viral testing: influenza (if antivirals considered or seasonal/outbreak), SARS-CoV-2 (per current public health guidance), RSV in select populations
Pertussis PCR (nasopharyngeal) if classic paroxysmal cough with whoop or exposure
Imaging
Chest radiograph NOT routinely needed — obtain if any of: HR >100, RR >24, T >38°C, focal exam findings (consolidation, rales), age >65, or immunocompromise — to exclude pneumonia
CDC/IDSA suggest CXR to differentiate from CAP when clinical picture is uncertain
Diagnostic algorithm
Feature
Acute Bronchitis
Pneumonia
Vitals
Often normal
Fever >38°C, HR >100, RR >24
Exam
Diffuse rhonchi/wheeze; no consolidation
Focal crackles, egophony, dullness
CXR
Normal — usually not needed
Lobar or interstitial infiltrate
Treatment
Symptomatic only
Antibiotic therapy
Course
Resolves in 1-3 weeks
Improves with appropriate antibiotics
Bedside differentiation of acute bronchitis from community-acquired pneumonia.
Treatment
First-line
Symptomatic and supportive care — antibiotics generally NOT indicated (high-value care)
Hydration, rest
Antitussives (dextromethorphan, benzonatate) for bothersome cough (modest evidence)
Honey 1-2 tsp (for adults and children ≥1 year) — evidence-based cough relief, particularly nocturnal
Throat lozenges, humidified air
Inhaled short-acting beta-agonist (albuterol) reasonable if wheeze or bronchospasm; not for all comers
NSAIDs or acetaminophen for fever or myalgia
Influenza-positive: oseltamivir 75 mg BID × 5 days if within 48 h of onset or high-risk patient
Second-line / adjunct
Antibiotics ONLY for documented or strongly suspected bacterial cause:
Pertussis (high public health priority): macrolide — azithromycin 500 mg day 1 then 250 mg × 4 days OR clarithromycin; primary benefit is reduced transmission
Mycoplasma or Chlamydophila (uncommon in true acute bronchitis): macrolide or doxycycline
Patient education on expected duration (cough up to 3 weeks; postinfectious up to 6-8 weeks) to reduce antibiotic-seeking
Re-evaluate if symptoms persist >3 weeks or worsen — consider pertussis, postnasal drip, asthma, GERD, ACEi cough, or alternative diagnosis
Educational use only. This outline is a study aid for PA students and is not medical advice or a substitute for clinical judgment. FirstPassPA is an independent study tool and is not affiliated with, endorsed by, or sponsored by NCCPA or PAEA. PANCE® and PANRE® are registered trademarks of the National Commission on Certification of Physician Assistants; End of Rotation™ is a program of the Physician Assistant Education Association.