VHOSPITAL.CLINIC · Differential Diagnosis
Fibromyalgia vs Lyme Disease
Clinical comparison — shared symptoms, key differences, distinguishing diagnostic tests, treatment pathways, and when to seek urgent evaluation.
Condition Overview
Condition A
Fibromyalgia
Fibromyalgia is a chronic condition causing widespread musculoskeletal pain, fatigue, sleep disturbance, and cognitive difficulties ("fibro fog"). Central sensitization is the underlying mechanism; multimodal treatment includes exercise, cognitive behavioral therapy, and medications.
Condition B
Lyme Disease
Lyme disease is a tick-borne bacterial infection caused by Borrelia burgdorferi, presenting with a bull's-eye rash (erythema migrans), flu-like symptoms, and if untreated, joint, neurological, and cardiac complications.
Shared Symptoms — Why They're Confused
Both conditions present with 6 overlapping symptoms, making clinical differentiation essential.
Key Clinical Differences
Fibromyalgia
- Chronic widespread musculoskeletal pain with fatigue
- No objective inflammatory markers (normal ESR, CRP)
- No history of tick bite or endemic exposure
- Diagnosed on clinical criteria (no serological test)
Lyme Disease
- Flu-like illness after tick bite; erythema migrans rash (bulls-eye)
- Arthritis, fatigue, neurological symptoms (Bell's palsy, meningitis)
- ELISA followed by Western blot confirmatory
- Endemic area exposure — North America, Europe
Distinguishing Diagnostic Tests
| Test | Fibromyalgia | Lyme Disease |
|---|---|---|
| Borrelia serology (ELISA + WB) | Negative — no Borrelia exposure | Positive ELISA confirmed by Western blot — Lyme disease |
| Inflammatory markers (ESR/CRP) | Normal — fibromyalgia is non-inflammatory | May be elevated during active Lyme infection |
| Skin examination | No rash | Erythema migrans (expanding annular rash) in early Lyme |
Treatment Approaches
Fibromyalgia
- •Multimodal: exercise, CBT, low-dose amitriptyline/duloxetine
- •No antibiotics (not an infection)
Lyme Disease
- •Doxycycline (early Lyme)
- •IV ceftriaxone for neurological or cardiac Lyme
- •Amoxicillin for children or pregnant women
When Doctors Consider Each Diagnosis
🔵 Consider Fibromyalgia when:
- →Chronic diffuse pain, normal serology, no tick exposure, no rash
🟢 Consider Lyme Disease when:
- →Tick bite history, erythema migrans, positive Borrelia serology
Explore Each Condition in Detail
Related Clinical Pages
Fibromyalgia
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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