What could be the cause of persistent body pains lasting over 3 months?

Persistent Body Pain for 3 Months: Diagnostic Approach

Body pain persisting for 3 months requires systematic evaluation to distinguish between inflammatory arthritis, chronic non-inflammatory conditions, and systemic diseases—with morning stiffness duration and joint swelling being the most critical discriminating features.

Initial Clinical Assessment

The first priority is determining whether this represents inflammatory versus non-inflammatory pain through specific historical features 1:

Key Discriminating Questions

• Morning stiffness duration: Stiffness lasting ≥60 minutes indicates inflammatory arthritis, while <30 minutes suggests osteoarthritis or mechanical causes 2
• Pain pattern: Inflammatory pain improves with movement and worsens with rest, often awakening patients in the second half of the night 2
• Joint involvement: Symmetric small joint involvement (wrists, metacarpophalangeal joints, proximal interphalangeal joints) suggests inflammatory arthritis 3, 4
• Visible swelling: The presence of actual joint swelling (synovitis) is essential for diagnosing inflammatory arthritis—pain alone without swelling may represent osteoarthritis or other non-inflammatory conditions 2

Physical Examination Priorities

Perform focused examination for 1, 4:

• Squeeze test: Lateral compression of metacarpophalangeal or metatarsophalangeal joints causing pain indicates inflammatory arthritis 2
• Joint swelling: Palpable synovitis in ≥3 joints, particularly involving small joints of hands/feet or knees 5
• Chest wall tenderness: Pain reproducible with palpation suggests musculoskeletal causes but does not exclude serious pathology 6
• Spinal mobility: Assess for axial spondyloarthropathy if chronic back pain (≥3 months) with insidious onset before age 45 2

Diagnostic Algorithm Based on Findings

If Morning Stiffness ≥60 Minutes + Joint Swelling Present

This mandates urgent rheumatology referral within 6 weeks 2, 5:

• Order inflammatory markers: ESR, CRP 1
• Order autoimmune markers: rheumatoid factor, anti-CCP antibodies, ANA 1, 4
• Check complete blood count, renal function, alkaline phosphatase, calcium, 25-hydroxy-vitamin D, parathyroid hormone, phosphate 1
• Consider HLA-B27 if spondyloarthritis suspected (back pain with inflammatory features) 1
• Obtain plain radiographs of affected joints to assess for erosions 1
• Consider ultrasound or MRI in doubtful cases to detect subclinical synovitis 2

If Morning Stiffness <30 Minutes Without Swelling

Consider osteoarthritis as primary diagnosis, particularly in patients over age 40 with characteristic joint involvement (distal interphalangeal, proximal interphalangeal, thumb base) 2:

• Simple investigations only: X-rays to exclude trauma, ESR for suspected inflammatory disease 1
• Avoid continuous cycle of investigations 1
• Implement biopsychosocial assessment rather than purely biomedical approach 1

If Widespread Body Pain Without Joint Swelling

Evaluate for fibromyalgia or chronic widespread pain 1:

• Chronic pain is defined as pain persisting >3 months or beyond normal tissue healing time 1
• Assess psychosocial factors that may increase pain and disability 1
• Consider that 11.2% of adults report daily pain, and chronic pain affects 30% of Americans 1
• First-line treatments for widespread pain include antidepressants (tricyclics, SNRIs), gabapentin/pregabalin, not opioids 1

If Bone Pain Persisting >6 Weeks

Consider chronic non-bacterial osteitis (CNO), particularly if atraumatic bone pain with inflammatory properties (pain irrespective of motion, nocturnal pain) 1:

• Requires multidisciplinary evaluation led by rheumatologist 1
• Perform whole-body imaging with MRI or bone scan to assess for multifocal involvement 1
• Differential diagnosis includes infectious osteomyelitis, malignant bone tumors, metabolic bone diseases 1

Red Flags Requiring Immediate Evaluation

If pain with inspiration is present, immediately exclude life-threatening causes 6:

• Pulmonary embolism (tachycardia, dyspnea in >90% of cases)
• Pneumothorax (unilateral absent breath sounds)
• Pneumonia (fever, localized pleuritic pain, friction rub)
• Pericarditis (pain worse supine, friction rub)
• Obtain ECG and troponin even if pleuritic features present 6

Common Pitfalls to Avoid

• Do not assume musculoskeletal cause based solely on chest wall tenderness—this reduces acute coronary syndrome probability but does not exclude pulmonary embolism, pneumothorax, or pneumonia 6
• Do not delay rheumatology referral if symptoms persist beyond 4-6 weeks with inflammatory features 3
• Do not diagnose inflammatory arthritis without objective joint swelling—morning stiffness alone may represent osteoarthritis with secondary inflammation 2
• Do not continue extensive investigations without biopsychosocial assessment—chronic pain often has entwined physical and psychosocial factors 1

Initial Management While Awaiting Specialist Evaluation

For suspected inflammatory arthritis with mild-moderate symptoms 3:

• NSAIDs (naproxen 500 mg twice daily) for 4-6 weeks as first-line therapy
• Assess response after 2-4 weeks
• Consider low-dose corticosteroids (prednisone 10-20 mg daily for 2-4 weeks) if inadequate response to NSAIDs after 4-6 weeks
• Avoid long-term NSAID use without monitoring for adverse effects

For non-inflammatory chronic pain 1:

• Develop pain management plan with patient including ongoing assessment
• Review management plan within 6 months
• Consider non-pharmacological interventions
• Avoid opioids as first-line treatment—evidence for long-term benefit in chronic non-cancer pain is limited 1