What is the first line of treatment for axial spondyloarthritis?

Diagnosis and Treatment of Axial Spondyloarthritis

Diagnostic Approach

Start with NSAIDs at the lowest effective dose as first-line pharmacological treatment for axial spondyloarthritis, combined with referral to a structured exercise program. 1

Clinical Recognition and Referral Criteria

Refer patients to a rheumatologist when they have back pain starting before age 45 that has lasted more than 3 months, plus at least 4 of the following features: 1

• Back pain beginning before age 35
• Waking at night requiring movement to alleviate symptoms
• Buttock pain
• Pain improvement with movement or within 2 days of taking an NSAID
• First-degree family member with spondyloarthritis
• Current or previous arthritis, enthesitis, or psoriasis

Refer even with only 3 criteria if HLA-B27 is positive. 1

Diagnostic Testing Strategy

Do not rule out spondyloarthritis based solely on negative laboratory results - neither negative HLA-B27, normal C-reactive protein, nor normal erythrocyte sedimentation rate excludes the diagnosis. 1 Axial spondyloarthritis occurs equally in men and women and can occur in HLA-B27 negative patients. 1

Imaging Protocol

• First-line imaging: Plain radiography of the sacroiliac joints in patients with mature skeletons. 1
• If radiography shows sacroiliitis meeting modified New York criteria, the diagnosis is confirmed. 1
• If radiography is negative or cannot be performed (immature skeleton), proceed to MRI of the sacroiliac joints. 1
• Follow-up MRI can be considered when diagnosis remains uncertain. 1
• Do not perform scintigraphy - it is not recommended. 1

First-Line Treatment Algorithm

Non-Pharmacological Management (Essential for All Patients)

All patients with axial spondyloarthritis must be referred to a specialist for a structured exercise program - this is not optional. 1, 2 Physical therapy may be more beneficial than home exercises alone for some patients. 2

Pharmacological First-Line Treatment

NSAIDs are the cornerstone of initial therapy and should be started at the lowest effective dose with continuous evaluation and monitoring. 1 The American College of Rheumatology suggests using NSAIDs at maximum tolerated doses while weighing individual risks and benefits. 2, 3

If the first NSAID is ineffective after 2-4 weeks, switch to a different NSAID. 1, 2 Continuous NSAID use is preferred for patients with active disease, while on-demand use is appropriate for stable disease. 2, 3

When to Escalate Beyond NSAIDs

Consider NSAID failure after 1 month of continuous use at adequate doses. 3 Escalate to biologic DMARDs when patients have: 1

• High disease activity despite use (or intolerance/contraindication) of at least two NSAIDs, AND
• Either elevated C-reactive protein, definite inflammation on MRI, or radiographic evidence of sacroiliitis

Second-Line Treatment: Biologic DMARDs

TNF inhibitors are the preferred first biologic agent for patients failing NSAIDs. 1, 4, 3 Current practice is to start with a TNF inhibitor before considering IL-17 inhibitors. 1

Special consideration: For patients with concomitant inflammatory bowel disease or recurrent uveitis, use TNF inhibitor monoclonal antibodies rather than etanercept. 4, 3

If the first TNF inhibitor fails: 1, 4

• For primary non-response: Consider switching to an IL-17 inhibitor
• For secondary non-response: Switch to a different TNF inhibitor

Treatment Targets and Monitoring

The primary treatment goal is clinical remission or inactive disease of musculoskeletal involvement. 2, 4 Monitor disease activity using clinical signs, symptoms, and acute phase reactants, adjusting treatment if targets are not reached. 2

Early diagnosis and treatment are crucial - there is typically a 5-7 year delay between first symptoms and diagnosis, yet 75% of patients show good response to NSAIDs within 48 hours. 2

Critical Pitfalls to Avoid

• Never use systemic glucocorticoids for long-term treatment of axial disease - they are strongly recommended against. 1, 4, 3
• Conventional synthetic DMARDs are not effective for predominant axial involvement and should not be used. 1
• Do not delay referral to rheumatology in patients meeting criteria - early intervention improves outcomes. 1
• Immediate ophthalmology referral is mandatory for any symptoms of uveitis (eye pain or redness). 1, 2

Peripheral Spondyloarthritis Treatment

For peripheral manifestations, the approach differs: 1, 2

• Nonprogressive monoarthritis: Corticosteroid injections first-line
• Peripheral polyarthritis, oligoarthritis, or persistent monoarthritis: Standard DMARDs are indicated
• NSAIDs can be added to DMARDs at the lowest effective dose