VHOSPITAL.CLINIC · Differential Diagnosis
Sarcoidosis vs Tuberculosis (TB)
Clinical comparison — shared symptoms, key differences, distinguishing diagnostic tests, treatment pathways, and when to seek urgent evaluation.
Condition Overview
Condition A
Sarcoidosis
Sarcoidosis is a multisystem inflammatory disease characterized by noncaseating granulomas, most commonly affecting the lungs and lymph nodes. It often resolves spontaneously but can cause progressive organ damage requiring corticosteroid treatment.
Condition B
Tuberculosis (TB)
Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis, primarily affecting the lungs with symptoms of chronic cough, night sweats, fever, and weight loss. Drug-resistant TB is a growing global health threat requiring prolonged combination antibiotic therapy.
Shared Symptoms — Why They're Confused
Both conditions present with 2 overlapping symptoms, making clinical differentiation essential.
Key Clinical Differences
Sarcoidosis
- Granulomatous disease of unknown cause — affects lungs, skin, eyes, CNS
- Bilateral hilar lymphadenopathy on CXR
- Elevated serum ACE; hypercalcaemia
- Non-caseating granulomas on biopsy
Tuberculosis (TB)
- Mycobacterium tuberculosis infection
- Upper lobe infiltrates, cavitation, or miliary pattern on CXR
- Positive Mantoux test / IGRA; AFB on sputum culture
- Caseating granulomas — central necrosis on biopsy
Distinguishing Diagnostic Tests
| Test | Sarcoidosis | Tuberculosis (TB) |
|---|---|---|
| Sputum / BAL culture for AFB | Negative — no mycobacterial growth | Positive AFB smear or M. tuberculosis culture — confirmatory |
| Interferon-gamma release assay (IGRA) | Negative (no TB exposure) | Positive — latent or active TB |
| Biopsy histology | Non-caseating epithelioid granulomas | Caseating (caseous necrosis) granulomas — TB hallmark |
Treatment Approaches
Sarcoidosis
- •Oral corticosteroids for symptomatic/organ-threatening disease
- •Methotrexate or hydroxychloroquine as steroid-sparing
Tuberculosis (TB)
- •Standard 6-month RHEZ regimen (rifampicin, isoniazid, pyrazinamide, ethambutol)
- •Directly observed therapy (DOT)
- •Contact tracing and notification
When Doctors Consider Each Diagnosis
🔵 Consider Sarcoidosis when:
- →Bilateral hilar lymphadenopathy, elevated ACE, non-caseating granuloma, IGRA negative
🟢 Consider Tuberculosis (TB) when:
- →Upper lobe cavitation, caseating granuloma, IGRA positive, AFB culture positive
Explore Each Condition in Detail
Related Clinical Pages
Sarcoidosis
Medical References
Content on this page is informed by evidence-based clinical sources including:
- World Health Organization (WHO)Global health guidance and disease classification
- National Health Service (NHS)UK clinical guidelines and patient information
- National Institute for Health and Care Excellence (NICE)Evidence-based clinical practice guidelines
- Centers for Disease Control and Prevention (CDC)US public health data and clinical recommendations
- PubMed – NCBIPeer-reviewed biomedical literature and clinical studies
- Cochrane LibrarySystematic reviews and meta-analyses in evidence-based medicine
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