What is the differential diagnosis and appropriate workup for a 49-year-old male with no significant past medical history presenting with acute severe lightheadedness, dizziness, vomiting, mild shortness of breath, and headache, after a recent household COVID-19 exposure?

Differential Diagnosis and Workup for Acute Severe Dizziness with Recent COVID-19 Exposure

Immediate Priority: Rule Out Life-Threatening Causes

This 49-year-old male with acute severe dizziness, vomiting, headache, mild dyspnea, and recent COVID-19 household exposure requires urgent evaluation for stroke, cardiac events, and COVID-19-related complications before considering benign causes. 1, 2

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Differential Diagnosis (Organized by Urgency)

Life-Threatening Causes (Must Rule Out First)

Acute Stroke/Posterior Circulation Ischemia:

• Acute dizziness with headache and vomiting is a classic presentation for posterior circulation stroke 3
• COVID-19 increases thrombotic risk with elevated D-dimer levels, predisposing to acute cerebrovascular events 1, 2
• Altered mental status and confusion are critical warning signs of CNS involvement, which occurs in 36.4% of all COVID-19 cases and 45.5% of severe cases 2

Acute Myocardial Infarction/Cardiac Arrhythmia:

• Myocardial dysfunction occurs in 20-30% of COVID-19 patients requiring ICU admission 1
• Presyncope with dyspnea suggests possible cardiac etiology 3
• Arrhythmias were noted in 44% of ICU patients with COVID-19 1

Pulmonary Embolism:

• COVID-19 causes hypercoagulability with propensity for thromboembolism 1
• Dyspnea accompanied by presyncope is a key feature 1
• Patients with COVID-19 appear hypercoagulable, and venous thromboembolism prophylaxis should be considered 1

Acute COVID-19 Infection:

• Recent household exposure is significant epidemiological risk 1, 4
• Headache is present in 7.2% of COVID-19 patients 4
• Dyspnea is associated with severe COVID-19 (odds ratio 2.43) 4
• Absence of fever does not exclude COVID-19, as only 58.6-77% present with fever 2
• Neurological symptoms may precede respiratory deterioration 2

Post-Acute Sequelae of SARS-CoV-2 (PASC)

PASC-Related Autonomic Dysfunction/POTS:

• Lightheadedness and dizziness are common features of PASC 1
• Dyspnea is commonly reported with PASC 1
• Chest pain is a common feature of POTS, though mechanisms remain poorly understood 1

Benign Causes (Consider After Excluding Above)

Benign Paroxysmal Positional Vertigo (BPPV):

• Most common cause of vertigo in primary care 3
• However, severe vomiting and associated dyspnea/headache make this less likely as sole diagnosis 3

Vestibular Neuritis:

• Can cause severe vertigo with vomiting 3
• Steroids are treatment if confirmed 3

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Immediate Workup and Interventions

Initial Assessment (Emergency Department)

Vital Signs and Orthostatic Testing:

• Measure blood pressure and heart rate supine, immediately upon standing, and at 2,5, and 10 minutes 1
• Orthostatic hypotension is defined by systolic BP drop ≥20 mmHg or diastolic BP drop ≥10 mmHg within 3 minutes 1
• POTS is defined by heart rate increase >30 bpm in adults ≥19 years during 10-minute active stand test 1
• Oxygen saturation ≤93-94% on room air requires immediate escalation of care 2
• Respiratory rate ≥30 breaths/minute indicates severe disease 2, 4

Neurological Examination:

• Assess for altered mental status, confusion, or focal neurologic deficits 1, 2
• Evaluate for nystagmus and perform Dix-Hallpike maneuver 3
• Check for corticospinal tract signs and meningeal signs 2
• Assess for cranial nerve palsies 1

Cardiac Examination:

• Auscultate for arrhythmias or murmurs 1
• Assess for signs of heart failure 1

Laboratory Testing (Order Immediately)

Basic Laboratory Panel:

• Complete blood count with differential (looking for lymphopenia, which is common in COVID-19) 1
• Basic metabolic panel (sodium, potassium, creatinine, glucose) 1
• Cardiac troponin (elevated in 20-30% with myocardial involvement) 1
• C-reactive protein (elevated in COVID-19 and inflammatory conditions) 1
• D-dimer (elevated in COVID-19 and thrombotic events; correlates with unfavorable stroke outcomes) 1
• Procalcitonin if available (helps distinguish bacterial co-infection) 1

COVID-19 Testing:

• Nasopharyngeal swab for RT-PCR (gold standard, sensitivity 60-78%) 4
• If initial RT-PCR is negative but symptoms persist, repeat testing should be considered as false negatives are common 4
• Consider serologic testing (IgG, IgM, IgA) if available 1

Additional Labs Based on Presentation:

• Blood gas analysis if hypoxemia suspected 1
• Thyroid function tests to exclude thyroid-related causes 1
• B-type natriuretic peptide if heart failure suspected 1

Imaging Studies (Order Based on Clinical Suspicion)

Electrocardiogram (ECG):

• Obtain immediately to assess for arrhythmias, ischemia, or conduction abnormalities 1
• Look for second or third-degree AV block or ventricular tachycardia 2

Chest Imaging:

• Chest X-ray or CT scan to evaluate for pneumonia, pulmonary embolism, or ground-glass opacities 1
• COVID-19 typically shows bilateral opacities, ground-glass opacities, and consolidation on CT 1
• CT pulmonary angiography if pulmonary embolism suspected (dyspnea with presyncope) 1

Head CT (Non-Contrast):

• Obtain urgently if stroke suspected (acute dizziness with headache and vomiting) 1
• Negative head CT does not exclude posterior circulation stroke; MRI may be needed 1

Brain MRI:

• Consider if head CT negative but high suspicion for stroke or encephalitis 1
• Look for diffusion restriction or FLAIR hyperintensity suggesting ischemia or inflammation 1

Cardiac Evaluation

Echocardiogram:

• Obtain to assess for myocardial dysfunction, pericarditis, or valvular abnormalities 1
• Myocardial dysfunction occurs in 20-30% of COVID-19 patients 1

Ambulatory Rhythm Monitor:

• 24-48 hour Holter monitor to exclude arrhythmias and define heart rate patterns 1
• Extended monitoring if episodic palpitations reported 1

Pulmonary Function Testing

Pulmonary Function Tests:

• Consider if dyspnea persists without clear cardiac or pulmonary abnormalities 1
• Assess for impaired diffusion capacity for carbon monoxide, which is common 6 months after COVID-19 hospitalization 1

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Immediate Interventions

Supportive Care:

• Supplemental oxygen if oxygen saturation ≤93% 2, 5
• Intravenous fluids if dehydrated from vomiting 5
• Antiemetics for nausea and vomiting 3

Isolation Precautions:

• Isolate immediately pending COVID-19 test results to prevent potential transmission 4

Thromboprophylaxis:

• Consider venous thromboembolism prophylaxis given COVID-19 exposure and hypercoagulable risk 1

Avoid NSAIDs Initially:

• Use acetaminophen for headache until COVID-19 is ruled out, as early concerns existed about NSAIDs potentially worsening COVID-19 outcomes 4

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Cardiology Consultation Indications

Immediate cardiology consultation is recommended for: 1

• Abnormal cardiac test results (elevated troponin, ECG changes, echocardiographic abnormalities) 1
• Persistent cardiopulmonary symptoms not otherwise explained 1
• Documented cardiac complications during SARS-CoV-2 infection 1

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Common Pitfalls to Avoid

Do not dismiss COVID-19 based on absence of fever alone, as only 58.6-77% of patients present with fever 2

Do not attribute all symptoms to benign vertigo without first excluding stroke, especially with headache and vomiting in the setting of COVID-19 exposure 1, 2, 3

Do not overlook neurological symptoms as early warning signs, as CNS involvement occurs in 36.4% of all COVID-19 cases and neurological symptoms may precede respiratory deterioration 2

Do not delay repeat COVID-19 testing if initial test is negative but clinical suspicion remains high, as sensitivity of nasopharyngeal RT-PCR is only 60-78% 4

Maintain high suspicion for bacterial superinfection in critically ill patients, as bacterial co-infection occurs in approximately 40% of viral respiratory infections requiring hospitalization 5

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Follow-Up and Monitoring

Re-evaluate within 24-48 hours or sooner if symptoms worsen, particularly if respiratory rate ≥30 breaths/min, oxygen saturation ≤93%, worsening dyspnea, new chest pain, or fever >38.5°C develops 5, 4

Monitor for progression to severe COVID-19, defined by respiratory rate ≥30 breaths/min, oxygen saturation ≤93%, or lung infiltrates >50% within 24-48 hours 4