What labs should be ordered for a rheumatologic workup in a patient with shortness of breath and chest discomfort, with a normal cardiac workup, including Electrocardiogram (EKG), Complete Blood Count (CBC), and chemistry, and an incidental finding of a pericardial cyst on Computed Tomography (CT) scan?

Rheumatologic Workup for a Young Adult with Shortness of Breath and Chest Discomfort

For a 20-year-old female with shortness of breath and chest discomfort who has had a normal cardiac workup and an incidental pericardial cyst, I recommend ordering ANA, RF, anti-CCP antibodies, ESR, CRP, and a complete metabolic panel as the initial rheumatologic workup.

Initial Laboratory Panel for Rheumatologic Evaluation

When evaluating a young patient with unexplained dyspnea and chest discomfort after ruling out primary cardiac causes, a systematic rheumatologic workup is essential. The incidental pericardial cyst is likely not causing her symptoms, as these are typically asymptomatic 1.

First-line Laboratory Tests:

• Complete Blood Count (CBC): To assess for anemia, leukocytosis, or thrombocytosis that may indicate inflammatory conditions 2
• Erythrocyte Sedimentation Rate (ESR): Non-specific marker of inflammation
• C-Reactive Protein (CRP): Acute phase reactant that rises with inflammation
• Antinuclear Antibody (ANA): Screening test for various autoimmune conditions
• Rheumatoid Factor (RF): Important for rheumatoid arthritis evaluation
• Anti-Cyclic Citrullinated Peptide (anti-CCP): More specific for rheumatoid arthritis than RF 3
• Complete Metabolic Panel: To assess organ function and electrolyte balance

Second-line Tests (if initial panel suggests specific conditions):

• Anti-dsDNA, Anti-Smith: If ANA is positive and SLE is suspected
• Anti-Ro/SSA, Anti-La/SSB: For Sjögren's syndrome evaluation
• Anti-Scl-70, Anti-centromere: If systemic sclerosis is suspected
• ANCA panel: For vasculitis evaluation if indicated by symptoms
• Myositis-specific antibodies: If muscle weakness or elevated muscle enzymes are present

Diagnostic Approach Based on Clinical Findings

Rheumatologic conditions can present with cardiopulmonary symptoms before joint manifestations appear 3. Pericardial involvement can be an early feature of conditions like rheumatoid arthritis, even without typical joint symptoms.

Key Clinical Considerations:

1. Systemic Lupus Erythematosus (SLE): Can present with pleuritis, pericarditis, and dyspnea
2. Rheumatoid Arthritis: May present with pericardial effusion as an initial manifestation 3
3. Inflammatory Myopathies: Can cause respiratory muscle weakness leading to dyspnea
4. Systemic Sclerosis: May cause pulmonary fibrosis or pulmonary hypertension
5. Mixed Connective Tissue Disease: Can affect multiple organ systems including lungs

Additional Diagnostic Considerations

If the rheumatologic workup is negative but symptoms persist, consider:

• Pulmonary Function Tests: To evaluate for restrictive or obstructive patterns 2
• High-Resolution CT of the Chest: To assess for interstitial lung disease not visible on standard CT
• Cardiopulmonary Exercise Testing: To differentiate between cardiac, pulmonary, and deconditioning causes of dyspnea 4, 2
• Six-Minute Walk Test: To objectively assess functional capacity 2

Important Caveats and Pitfalls

• Beware of premature closure: Don't assume the pericardial cyst is causing symptoms, as these are typically asymptomatic incidental findings 1
• Consider overlapping syndromes: Rheumatologic conditions often have overlapping features
• Watch for evolving presentations: Autoimmune conditions may evolve over time with new manifestations
• Don't forget non-rheumatologic causes: Consider pulmonary hypertension, interstitial lung disease, or other conditions that may mimic rheumatologic disease 2
• Medication effects: Some medications can cause drug-induced lupus or other autoimmune phenomena

By following this systematic approach to rheumatologic evaluation in this young patient with unexplained dyspnea and chest discomfort, you can identify potential autoimmune conditions that may be causing her symptoms while avoiding unnecessary testing.