What is the initial management and workup for a teenager presenting with sacroiliitis?

Initial Management and Workup for Sacroiliitis in Teenagers

For teenagers presenting with sacroiliitis, the initial workup should include MRI of the sacroiliac joints and treatment should begin with NSAIDs, with progression to TNF inhibitors if symptoms persist despite NSAID therapy. 1

Diagnostic Workup

Imaging

• MRI is the imaging modality of choice for suspected sacroiliitis in teenagers 2

  • Required sequences:
    • Coronal oblique T1-weighted
    • Fluid-sensitive sequences
    • Perpendicular axial oblique sequence
    • Sequence for optimal evaluation of bone-cartilage interface
  • Both active inflammatory and structural lesions should be documented

• Alternative imaging options when MRI is unavailable:

  • Low-dose CT scan (especially for evaluating structural lesions) 2
  • Radiography (less sensitive for early disease)
  • Dual-energy CT with virtual non-calcium images can detect bone marrow edema 2

Important Diagnostic Considerations

• Normal imaging features in children (flaring, blurring, irregular articular surface) can mimic disease 2
• Sacroiliac joint dysfunction accounts for up to 25% of cases of lower back pain 3, 4

Treatment Algorithm

Step 1: Initial Treatment

• Begin with NSAID therapy (strongly recommended over no treatment) 1
  • Continue for at least 4 weeks to assess response
  • Monitor for clinical improvement in pain and function

Step 2: For Patients with Inadequate Response to NSAIDs

• Add TNF inhibitor therapy (strongly recommended over continued NSAID monotherapy) 1
  • Options include etanercept, adalimumab, infliximab, or golimumab
  • TNFi is preferred over methotrexate monotherapy, which is strongly discouraged for sacroiliitis 1

Step 3: Adjunctive Therapies

• Consider bridging therapy with oral glucocorticoids (limited course <3 months) 1

  • Most useful in cases with:
    • High disease activity
    • Limited mobility
    • Significant symptoms

• Consider intraarticular glucocorticoid injections of the sacroiliac joints 1, 5

  • CT-guided injections have shown effectiveness in juvenile spondyloarthropathy 5
  • 87.5% of patients showed significant decrease in pain within 1-2 weeks after injection 5

• Physical therapy is conditionally recommended for patients with functional limitations 1

  • Focus on:
    • Identifying and reducing mechanical factors contributing to microtrauma
    • Reducing repetitive stress that could potentially contribute to disease activity

Step 4: For Patients with Contraindications to TNFi or TNFi Failure

• Consider sulfasalazine (conditionally recommended) 1
  • Note: Efficacy is relatively limited compared to TNFi

Treatment Pitfalls and Caveats

1. Avoid methotrexate monotherapy for sacroiliitis 1

   • Methotrexate may be useful as adjunct therapy for concomitant peripheral polyarthritis
   • May help prevent development of anti-drug antibodies against monoclonal TNFi

2. Monitor for disease progression despite symptom improvement 5

   • Up to one-third of patients may show progression of joint destruction despite absence of subjective complaints

3. Consider surgical options only after failure of comprehensive medical management 6

   • Reserved for patients with:
     • Positive response to SI injection with >75% relief
     • Failure of all nonsurgical treatments
     • Continued or recurrent SIJ pain

4. Recognize that early diagnosis and treatment are crucial to prevent irreversible structural damage to the sacroiliac joints 2