Respiratory · airway localization
A cold can start the story, but the diagnosis changes the moment the exam moves from the nose and pharynx down into the bronchial tubes. Diffuse bilateral wheezes and faster breathing mean the lower airways are inflamed, so acute bronchitis beats the viral URI reflex. Locate the sound by anatomy first, then name the illness.
When a stem hands you a post-cold cough, do not autopilot to viral URI. Put the stethoscope on the anatomy. A quiet nose and throat with diffuse bilateral wheezes and a rising respiratory rate is the lower airway talking. That is acute bronchitis. Know your clues and the trap stops working on you.
Opening challenge
A healthy 27-year-old daycare worker has five days of cough after a mild scratchy throat. Temperature is 37.7 C, respiratory rate is 24/min, and oxygen saturation is 98% on room air. Lung exam reveals diffuse end-expiratory wheezes on both sides. The nasal mucosa is quiet, the oropharynx has no exudate, and there is no posterior pharyngeal drainage track. Which diagnosis best explains the pattern?
Airway theater
Press the stages. The illness can begin in the nose and throat, but inflammation can descend into the bronchial tubes. Narrowed, mucus-filled bronchi turn airflow turbulent, and that turbulence is the wheeze you hear on both sides.
Tap a stage
Many cases open like a common cold: a scratchy throat, a little congestion, mild cough. At this point the upper airway is the irritated tissue, and the lungs are still clear.
Locate the sound
The trick is not memorizing five illnesses. It is letting the abnormal finding pick the floor of the airway first, then confirming with the associated clues. Nose, sinus, throat, or bronchi.
Lower airway
Bronchial inflammation after a respiratory infection. The chest is where the action is: diffuse bilateral wheezesWheeze is generated by turbulent airflow through narrowed bronchi. Diffuse and bilateral, with a rising respiratory rate, points below the larynx. or rhonchi, often with mild tachypnea. The case may open like a cold, but the lung exam decides it.
Upper airway
Congestion, rhinorrhea, and sore throat with clear lungsViral URI is an upper-airway mucosal infection. It can cough from drainage, but it does not produce diffuse bilateral wheeze the way bronchitis does.. Cough can come from postnasal drip, but the respiratory rate is usually not the clue and the chest stays quiet.
Nose
Sneezing, itching, and watery rhinorrhea with eye symptoms. The exam lock is pale, boggy turbinatesAllergic rhinitis is a histamine-driven nasal story. Boggy turbinates and a nasal smear with eosinophils confirm it; the lungs stay clear.. No fever pattern, clear lungs, and a seasonal or exposure trigger.
Sinus
Facial pain or pressure with purulent drainageBacterial sinusitis is favored by symptoms beyond 10 days, double-worsening, fever, and purulent drainage with facial tenderness., and symptoms lasting at least 10 days or double-worsening. A quiet nose with no drainage track makes it a weak fit.
Throat
Fever, tonsillar exudatesGroup A strep pharyngitis centers on exudative tonsils and tender anterior cervical nodes, and cough is usually absent. Wheezing lungs are the wrong organ system., and tender anterior cervical nodes. Cough is usually absent. Wheezing lungs are the wrong organ system entirely.
Do not name the disease before you locate the sound. A wheeze is a lung clue, not a nose clue. Itch and boggy turbinates are allergy. Facial pressure with purulence and a long course is the sinus. Exudates and tender nodes with no cough is the throat. Make the anatomy answer first, every time.
Sort the look-alikes
These ride together in board questions because they share cough or viral timing. The trick is keeping their airway level and signature clues apart. Tap each tab.
Bronchial inflammation after a respiratory infection. Diffuse bilateral wheezes or rhonchi can appear, and the respiratory rate can rise because bronchial resistance increased. The case may begin like a cold, but the lung exam becomes the deciding clue. If the lungs wheeze diffusely, stop treating the case as a nose-only illness.
An upper-airway mucosal infection with nasal congestion, rhinorrhea, sore throat, or cough from drainage. The lungs are usually clear and the respiratory rate is usually not the clue. URI can cough, but it does not explain bilateral wheeze as cleanly as bronchitis. URI lives above the larynx unless the lung exam says otherwise.
Sneezing, itching, watery rhinorrhea, and eye symptoms, with pale or boggy turbinates as the exam lock and a nasal smear that can show eosinophils. No fever pattern and usually clear lungs. Without itch, sneezing, watery symptoms, or boggy turbinates, it loses. Allergic rhinitis needs nasal allergy clues, not bronchial wheeze alone.
Facial pain or pressure, purulent nasal drainage, and symptoms lasting at least 10 days or double-worsening. A quiet nose with absent posterior drainage makes it a weak fit. Sinusitis earns the answer with the time course plus purulence or facial pressure, not with a diffuse wheeze.
Fever, tonsillar exudates, and tender anterior cervical nodes, with cough usually absent. Rapid antigen testing or throat culture can support it. Wheezing lungs are the wrong organ system. Strep needs a throat pattern and the absence of cough, not diffuse wheeze.
