In a patient with back stiffness, negative HLA‑B27, normal spine MRI, negative rheumatoid arthritis and ANA labs, and normal back‑muscle EMG, what medication can be recommended to relieve the stiffness?

Medication Recommendation for Back Stiffness with Negative Workup

Start NSAIDs at full dose as first-line treatment for your back stiffness, specifically naproxen 500mg twice daily or another NSAID at the lowest effective dose. 1

Rationale for NSAID Therapy

Your clinical presentation—back stiffness with negative HLA-B27, normal spine MRI, negative rheumatoid arthritis tests, and normal EMG—does not rule out axial spondyloarthritis or other inflammatory conditions. Here's why NSAIDs are appropriate:

Why NSAIDs Despite Negative Tests

• Negative HLA-B27 does not exclude spondyloarthritis: Approximately 10% of ankylosing spondylitis cases are HLA-B27 negative, and the diagnosis cannot be ruled out based on laboratory results alone. 2, 3

• Normal inflammatory markers (CRP/ESR) do not exclude disease: Only 50% of patients with active axial spondyloarthritis have elevated inflammatory markers, so normal values should not prevent treatment. 2

• Normal MRI does not rule out early disease: Radiographic changes may not be present in early stages, and clinical symptoms should guide initial management. 4

Evidence Supporting NSAID Use

• NSAIDs are first-line pharmacological treatment for axial spondyloarthritis and inflammatory back conditions, recommended by the European League Against Rheumatism at full dose immediately. 5

• 75% of patients with axial spondyloarthritis show good response to NSAIDs within 48 hours, making this both diagnostic and therapeutic. 5

• Naproxen is FDA-approved specifically for relief of signs and symptoms of ankylosing spondylitis, as well as for management of pain and other inflammatory conditions. 1

Specific Medication Recommendation

Naproxen 500mg twice daily (or equivalent NSAID):

• Use the lowest effective dose for the shortest duration consistent with treatment goals 1
• Assess response within 48-72 hours 5
• If significant improvement occurs with NSAIDs, this actually increases the likelihood of underlying inflammatory spondyloarthritis and warrants rheumatology referral 3, 5

Critical Next Steps

When to Refer to Rheumatology

You should be referred to a rheumatologist if you have:

• Chronic back pain >3 months with onset before age 45 3, 5
• Morning stiffness >30 minutes 2
• Night or early-morning pain that awakens you 2
• Improvement with exercise but not with rest 2
• Good response to NSAIDs within 48 hours 5

Even with negative HLA-B27, if you have inflammatory back pain characteristics, referral is warranted. 2, 3

Common Pitfalls to Avoid

• Do not assume negative tests rule out inflammatory disease: The combination of negative HLA-B27, normal inflammatory markers, and normal imaging does not exclude spondyloarthritis or other inflammatory conditions requiring treatment. 2, 3

• Do not delay NSAID trial: Waiting for definitive diagnosis before treating symptoms is inappropriate when NSAIDs are safe and effective first-line therapy. 5

• Monitor for NSAID response: Dramatic improvement with NSAIDs (within 48 hours) is itself a diagnostic clue suggesting inflammatory pathology and should prompt rheumatology evaluation. 5

Treatment Goals

• Alleviate stiffness and pain 4
• Improve functioning and maintain work ability 4
• Assess whether symptoms are NSAID-responsive (suggesting inflammatory etiology) 5
• Determine need for specialist evaluation based on response 3, 5