What are the potential causes and management strategies for a patient, possibly with a history of respiratory issues such as chronic obstructive pulmonary disease (COPD) or asthma, who reports smelling smoke?

Phantosmia (Smelling Smoke When None is Present)

If a patient reports smelling smoke when no smoke is present, this is phantosmia—a neurological symptom, not a respiratory one—and requires urgent neurological evaluation to rule out seizure disorders, brain tumors, or stroke, particularly if accompanied by other neurological symptoms.

Critical Distinction: Actual vs. Phantom Smoke

The provided evidence addresses respiratory diseases (COPD, asthma) and their relationship to actual smoke exposure 1. However, "smelling smoke" as a chief complaint typically refers to phantosmia—perceiving smoke odor without an external source—which is a neurological phenomenon requiring a completely different diagnostic approach.

If Patient is Smelling Phantom Smoke (Phantosmia)

Immediate Neurological Assessment Required

• Evaluate for seizure activity: Olfactory hallucinations are a classic feature of temporal lobe epilepsy, particularly involving the uncinate gyrus
• Screen for focal neurological deficits: Check for weakness, speech changes, visual field defects, or altered mental status that might indicate stroke or mass lesion
• Assess for other sensory disturbances: Phantosmia may accompany migraines, head trauma, or neurodegenerative diseases
• Obtain urgent neuroimaging: MRI brain with contrast is indicated if phantosmia is persistent, progressive, or accompanied by any neurological symptoms

Common Pitfalls to Avoid

• Do not attribute phantosmia to respiratory disease: While COPD patients may have chronic cough and sputum production 1, they do not experience olfactory hallucinations from their lung disease
• Do not delay neurological workup: Phantosmia can be the presenting symptom of serious intracranial pathology requiring urgent intervention

If Patient is Actually Exposed to Smoke

For Active Smoke Inhalation Injury

• Ensure airway patency immediately: Early intubation with fiberoptic bronchoscopy is prudent before airway edema develops 2
• Provide supplemental oxygen: Target saturation 94-98% for most patients, or 88-92% if COPD is suspected pending arterial blood gas results 3
• Obtain chest radiograph urgently: To identify pneumonia, pulmonary edema, or other acute pathology 3

For Chronic Smoke Exposure (Tobacco or Environmental)

• Implement aggressive smoking cessation: This is the only intervention proven to reduce mortality and slow disease progression in COPD 4. Use combination pharmacotherapy (nicotine replacement plus bupropion or varenicline) with intensive behavioral counseling 4
• Perform spirometry: Required to diagnose COPD, with post-bronchodilator FEV1/FVC <0.70 confirming persistent airflow limitation 1, 3
• Assess for occupational/environmental exposures: Indoor pollution from biomass cooking, occupational dusts, and passive smoke exposure all contribute to COPD risk 1

Smoking Cessation as Primary Intervention

• Advise abrupt cessation rather than gradual reduction: Gradual withdrawal rarely achieves complete cessation 1, 4
• Provide intensive support for heavy smokers: Those with multiple previous quit attempts require even more intensive support and should be counseled that repeated attempts are often necessary 1, 4
• Treat tobacco use as a primary intervention: Systematic assessment at every visit is essential 3, 4

Algorithmic Approach to "Smelling Smoke" Complaint

1. Clarify the complaint: Is smoke actually present, or is the patient experiencing an olfactory hallucination?
2. If phantom smell: Proceed with neurological evaluation (history of seizures, headaches, trauma; neurological exam; brain MRI)
3. If actual smoke exposure: Assess for acute inhalation injury (airway compromise, hypoxia) vs. chronic exposure (smoking history, occupational exposures)
4. If chronic smoker: Perform spirometry, initiate smoking cessation, and manage COPD if present 1, 3, 4