What is inflammatory back pain and how is it different from ordinary back pain?

Inflammatory back pain has a specific pattern — insidious onset before age 40, lasting over three months, with morning stiffness that improves with movement but not rest, and often nocturnal pain waking you in the second half of the night. Ordinary mechanical back pain is typically worse with movement and better with rest. The distinction matters because inflammatory back pain is the primary clinical pointer for axial spondyloarthritis, and its presence signals the need for targeted investigation and rheumatology referral rather than reassurance and analgesia alone.

What tests will my GP order to check for axial spondyloarthritis?

Your GP will likely request HLA-B27 (a genetic marker present in 80–95% of Australians with ankylosing spondylitis), CRP and ESR (inflammation markers — which can be normal even in active disease), and blood tests checking kidney and liver function before medications. X-rays of the sacroiliac joints and lumbar spine are usually first-line imaging. If X-rays are normal but clinical suspicion remains high, MRI of the sacroiliac joints with STIR sequences detects bone marrow oedema — the earliest sign of active sacroiliitis. Rheumatologist referral is typically needed to access Medicare-funded MRI.

What does biologic therapy involve and how is it accessed in Australia?

TNF inhibitors — adalimumab, etanercept, infliximab, golimumab, certolizumab — are PBS-listed for ankylosing spondylitis through the Section 100 Authority programme. Eligibility requires meeting ASAS classification criteria, a BASDAI symptom score of four or more, evidence of active inflammation on blood tests or MRI, and failure of at least two NSAID trials. Biologics are initiated and supervised by a rheumatologist. Before starting, screening for latent tuberculosis, hepatitis B and C, and vaccination update are required. Many patients access biosimilar versions, which are equally effective and routinely available.

Can I exercise with ankylosing spondylitis, and what type is recommended?

Yes — daily exercise is one of the most important long-term strategies for axial spondyloarthritis. Extension-biased spinal exercises counteract the kyphotic posture the disease drives toward; cardiorespiratory fitness reduces cardiovascular risk; and physiotherapy-supervised group programmes are superior to home exercise alone. Aquatic exercise is excellent for low-impact full-range movement, especially during flares. Under a GP Chronic Condition Management Plan, Medicare-subsidised physiotherapy and exercise physiology visits are available. Rest alone is not recommended — movement reduces morning stiffness rather than worsening it.

What warning signs in axSpA should I act on urgently?

The most important is sudden eye pain and redness — anterior uveitis affects about 30% of people with axSpA and requires same-day ophthalmology review to prevent permanent damage. Persistent bowel symptoms (diarrhoea, blood, weight loss) can indicate inflammatory bowel disease, which coexists in about 10% of cases. In people with long-standing fused-spine disease, even a minor fall or bump can cause a serious spinal fracture — treat any spinal trauma as an emergency. New chest pain or a heart murmur warrants cardiovascular evaluation.

Ankylosing spondylitis & axial spondyloarthritis

Ankylosing spondylitis & axial spondyloarthritis: the GP guide

By Dr HB Lo, FACRRM Reviewed 27 June 2026 11 min read

Axial spondyloarthritis (axSpA) affects 0.5–1% of Australians with chronic sacroiliac and spinal inflammation. Diagnosis averages eight to ten years from onset.

The diagnostic pointer is inflammatory back pain in adults under 45 — insidious onset, morning stiffness improving with movement, nocturnal pain. First-line care combines exercise, physiotherapy, and continuous NSAIDs, which carry disease-modifying evidence in ankylosing spondylitis.

PBS-listed biologic therapy is available for active disease failing two NSAID trials, initiated by a rheumatologist. Annual monitoring covers eyes, cardiovascular risk, and bone density.

What ankylosing spondylitis actually is

Axial spondyloarthritis (axSpA) is a chronic immune-mediated inflammatory disease of the sacroiliac joints and spine. It encompasses two subtypes distinguished by imaging: radiographic axSpA — historically called ankylosing spondylitis (AS) — where sacroiliitis is visible on plain X-ray, and non-radiographic axSpA (nr-axSpA) where bone marrow oedema in the sacroiliac joints is detectable on MRI before X-ray changes appear. Nr-axSpA often represents the earlier stage, and both are now managed within the same treatment framework.

Despite affecting an estimated 0.5–1% of Australians across the full axSpA spectrum, the average time from symptom onset to diagnosis has historically been eight to ten years. The majority of patients present first in general practice with back pain, and the diagnostic hinge is whether that pain is inflammatory in character — a distinction that transforms the clinical pathway entirely. RACGP AFP guidance highlights that GPs are the primary entry point and that shortening the diagnostic delay supports timely access to effective therapy.

The broader spondyloarthritis family includes peripheral forms — psoriatic arthritis, IBD-associated (enteropathic) arthritis, reactive arthritis, and undifferentiated peripheral SpA — sharing pathophysiology, HLA-B27 association, and characteristic extra-articular features with axSpA.

A. Core clinical — the AU general-practice framework

Recognising inflammatory back pain

The key to suspecting axSpA is identifying inflammatory back pain (IBP). ASAS classification criteria (Rudwaleit Ann Rheum Dis 2009) use the Calin/ASAS set — IBP is present when four or more of the following apply:

Insidious onset
Age at onset under 40
Duration of three months or more
Morning stiffness improving with exercise and movement
Improvement with exercise but not with rest
Nocturnal pain waking the patient in the second half of the night
Alternating buttock pain

IBP alone does not confirm axSpA, but its presence in a young adult with chronic back pain triggers the appropriate workup and signals referral. The contrast with mechanical back pain — worse with activity and better with rest — is quickly assessed in history.

Extra-articular features as diagnostic clues

Three extra-articular associations occur in 10–30% of patients and sometimes present before or alongside spinal disease:

Anterior uveitis (~30%) — recurrent, unilateral, acute red eye with photophobia and pain. Requires same-day ophthalmology referral. An HLA-B27-positive person presenting with recurrent anterior uveitis warrants axSpA screening even without back symptoms.
Inflammatory bowel disease (~10%) — Crohn’s disease more commonly than ulcerative colitis. Screen with stool calprotectin (MBS 66520) if bowel symptoms are present.
Psoriasis (~10%) — inspect the scalp, umbilicus, gluteal cleft, and nail plates for pitting and onycholysis.

Enthesitis — inflammation at tendon and ligament insertions — is characteristic: Achilles heel pain, plantar fasciitis-like presentation, and iliac crest tenderness in a young adult are all SpA pointers.

Initial workup in general practice

HLA-B27 (MBS 71089) — positive in 80–95% of Caucasian Australians with AS, compared with 7% of the background population. Supportive but neither necessary nor sufficient for diagnosis. A negative result does not exclude axSpA, particularly in people of Asian or Indigenous background.

CRP and ESR — inflammatory markers are elevated in most active cases, but can be normal in up to 40% of patients with active axSpA. Normal inflammatory markers do not rule out disease.

FBC, UEC, LFT — baseline before commencing NSAIDs or any immunomodulatory therapy.

Imaging:

X-ray sacroiliac joints and lumbar spine — first-line in general practice. Assess for sacroiliitis (sclerosis, erosion, joint space narrowing graded 0–4 by Modified New York criteria), syndesmophytes, and vertebral squaring. Normal X-rays do not exclude nr-axSpA.
MRI sacroiliac joints with STIR sequences — gold standard for nr-axSpA; bone marrow oedema signals active sacroiliitis. Rheumatologist referral is generally required for Medicare-funded MRI in this context.

Examination essentials

Physical findings may be subtle in early disease:

Modified Schober’s test — mark L5 and points 10 cm above and 5 cm below; lumbar flexion should increase the span by at least 5 cm
Occiput-to-wall distance — any gap from zero indicates established thoracic kyphosis; track serially
Chest expansion at the fourth intercostal space — normal ≥5 cm; under 2.5 cm is abnormal (costovertebral joint involvement)
FABER (Patrick’s) test — sacroiliac joint stress
Skin and nail inspection for psoriasis; peripheral joint count; Achilles and heel tenderness

B. The treatment ladder — NSAIDs, biologics, and long-term disease management

Non-pharmacological foundations

ASAS-EULAR 2022 recommendations for management of axSpA place non-pharmacological approaches as the lifelong cornerstone alongside any medication.

Daily exercise is essential — extension-biased spinal flexibility, postural correction, and cardiorespiratory fitness. Supervised group physiotherapy is superior to unsupervised home programmes. Under a GP Chronic Condition Management Plan (GPCCMP) (MBS 965/967, from July 2025), five allied health visits per year including physiotherapy and exercise physiology are Medicare-subsidised.

Smoking cessation is a disease-modification priority: smoking accelerates radiographic progression and reduces biologic therapy response. Quitline 13 7848, nicotine replacement therapy, and varenicline are accessible through general practice.

Workplace ergonomics — desk setup, driving posture, lifting technique — with occupational therapy review if needed. Supine sleeping with one low pillow and aquatic exercise during flares are practical adjuncts.

First-line pharmacotherapy — continuous NSAIDs

NSAID therapy for active axSpA is both symptomatic and disease-modifying. Wanders et al. (Arthritis & Rheumatism 2005) demonstrated in a two-year RCT that continuous full-dose NSAID therapy slowed radiographic progression compared with on-demand use — an effect that underpins the ASAS-EULAR 2022 recommendation for continuous use in symptomatic active disease.

Rotate between agents (naproxen, celecoxib, indomethacin) if the initial response is inadequate. Co-prescribe a proton pump inhibitor for gastrointestinal protection. Review blood pressure, renal function, and cardiovascular risk at every follow-up consultation.

Second-line — biologic therapy

When disease remains active despite at least two NSAID trials at maximum tolerated dose for a minimum of three months each, biologic therapy is the next step — initiated and supervised by a rheumatologist.

TNF inhibitors — adalimumab, etanercept, infliximab, golimumab, certolizumab — are first-line biologics. PBS Section 100 (Efficient Funding of Chemotherapy) Authority listing applies when: ASAS axSpA criteria are met, BASDAI score ≥4, elevated CRP or active MRI sacroiliitis demonstrated, and failure of ≥2 NSAIDs. Biosimilars of adalimumab, etanercept, and infliximab are routinely dispensed.

IL-17 inhibitors — secukinumab and ixekizumab — are third-line after TNF inhibitor failure or contraindication. Critically: IL-17 inhibitors worsen inflammatory bowel disease flares and are contraindicated in any patient with axSpA and coexistent IBD. TNF inhibitors remain the preferred biologic when IBD overlap is present.

JAK inhibitors — upadacitinib and tofacitinib — are PBS Authority-listed fourth-line. The SELECT-AXIS 2 trial (Lancet 2022) demonstrated upadacitinib superiority in TNF inhibitor-refractory axSpA. Both carry TGA black-box warnings based on the RA ORAL Surveillance data (NEJM 2022) showing increased cardiovascular events, VTE, and malignancy risk — use with greater caution in adults over 65, current smokers, and those with prior cardiovascular disease or malignancy.

Sulfasalazine — has a role in peripheral SpA arthritis but has no proven efficacy for axial disease; not recommended for spinal manifestations.

Pre-biologic screening — essential documentation

Before commencing any biologic or JAK inhibitor:

Hepatitis B surface antigen, anti-HCV antibodies, HIV serology
QuantiFERON-TB (MBS 69487) — latent TB must be treated before starting
Vaccinations: PCV20, influenza, COVID-19, Shingrix (recombinant zoster). Live vaccines are contraindicated on biologic therapy — do not administer Zostavax, yellow fever, MMR, or varicella on a biologic

C. Comorbidity surveillance and long-term monitoring

Annual ophthalmology review

Anterior uveitis affects up to 30% of patients with axSpA and may occur even in well-controlled disease. Counsel every patient to present same-day to any emergency ophthalmic service for acute red, painful eye — delay risks synechiae formation and visual loss. Annual baseline ophthalmology review is appropriate in established axSpA.

Annual cardiovascular risk assessment

AxSpA confers approximately twice the background cardiovascular risk independent of traditional risk factors. Annual formal cardiovascular risk calculation, with appropriate blood pressure, lipid, and glucose management, is standard care. Document aortic regurgitation murmur status in long-standing disease — an echocardiogram is warranted if detected.

Bone density — DXA every two to three years

Paradoxical osteoporosis occurs in axSpA despite pathological new bone formation (syndesmophytes). Vertebral fracture risk is elevated two- to fourfold. Request lateral spine or femoral neck DXA — lumbar AP DXA is falsely elevated by syndesmophyte calcification and will underestimate fracture risk. Qualifying criteria for DXA under MBS 12306 include chronic inflammatory disease.

Spinal fracture risk in late fused-spine disease

An ankylosed spine is highly vulnerable to fracture on minor trauma. Any fall or spinal trauma in a person with known fused-spine AS requires urgent CT or MRI of the full spine even if the patient is neurologically intact — unstable cervical fractures occur from minimal force. Spinal manipulation is absolutely contraindicated in late or fused disease. Pre-anaesthetic flexion-extension cervical X-ray is recommended before elective surgery in long-standing AS.

Mental health

Depression and anxiety are prevalent in axSpA — chronic pain, sleep disruption, and functional limitation all contribute. Mental Health Care Plan (MBS 2715/2717) with psychology referral is integral to whole-person care. Arthritis Australia and Spondylitis Australia provide peer support and condition-specific education.

Vaccination review on biologic therapy

Annual influenza; COVID-19 boosters per national schedule; Shingrix (recombinant — safe on biologic, preferred over live Zostavax which is contraindicated); pneumococcal PCV20 review every five years. Screen hepatitis B immunity before TNF inhibitor commencement and vaccinate if non-immune.

D. Australian operations

MBS items

Key Medicare items for axSpA management in general practice:

Service	MBS items
Standard GP consultations	23, 36, 44
Telehealth (existing relationship)	91790, 92029, 92060
GPCCMP (from July 2025)	965, 967
Allied health under GPCCMP (physio, EP, dietitian — 5 visits/year)	10960 range
Mental Health Care Plan + psychology	2715, 2717, 80000–80020
HLA-B27	71089
CRP / ESR / FBC / UEC / LFT	66503, 65060, 65070, 66500, 66512
Stool calprotectin	66520
QuantiFERON-TB (pre-biologic)	69487
X-ray SI joints / lumbar spine	58300, 58301
DXA (qualifying criteria)	12306
ECG	11700
Specialist referrals	105, 106

PBS prescribing

NSAIDs (naproxen, celecoxib, ibuprofen, diclofenac, indomethacin) are available on the general PBS schedule. Proton pump inhibitors are on the general schedule for co-prescription. Biologic and targeted synthetic DMARDs are PBS Section 100 Authority — rheumatologist-initiated. Bisphosphonates (alendronate, risedronate, zoledronic acid) are PBS Authority-listed for qualifying osteoporosis. Full drug schedules at pbs.gov.au.

Referral pathways

Scenario	Referral	Urgency
Inflammatory back pain + SpA features	Rheumatology	Routine
Active anterior uveitis	Ophthalmology	Same-day
Bowel symptoms in axSpA	Gastroenterology	Routine
Refractory disease on NSAIDs	Rheumatology — biologic candidacy	Soon
Trauma / fall in known fused-spine AS	Emergency + spinal surgery	Urgent
Pregnancy planning on biologic	Rheumatology + obstetrics	Pre-conception
New aortic regurgitation murmur	Cardiology + echocardiogram	Routine

AxSpA qualifies as a chronic condition for GPCCMP, enabling coordinated allied health and specialist management under Medicare.

E. Special populations

Women with axSpA. Historically under-diagnosed due to the misconception that AS predominantly affects men. Non-radiographic axSpA approaches a 1:1 sex ratio — women more often present with atypical or peripheral disease, and diagnostic delay is greater. Certolizumab pegol is the preferred TNF inhibitor in pregnancy — it has minimal placental transfer and is the only biologic with reassuring safety data through conception and the third trimester. Methotrexate and leflunomide are teratogenic and must cease at least three months before attempting conception. Sulfasalazine is pregnancy-compatible with folate supplementation.

Aboriginal and Torres Strait Islander peoples. HLA-B27 prevalence varies across Indigenous populations and is lower in some groups — a negative result does not exclude axSpA. The ATSI Health Assessment (MBS 715) provides a structured opportunity for systematic musculoskeletal review. Culturally safe care is available through NACCHO-affiliated services.

Older adults. Diffuse idiopathic skeletal hyperostosis (DISH) is an important differential in those over 50 — it produces flowing anterior vertebral osteophytes, spares the sacroiliac joints, and is HLA-B27 negative. JAK inhibitors warrant greater caution in people aged over 65 with cardiovascular risk factors, prior VTE, or history of malignancy.

Adolescents. Onset in the teenage years is common. Juvenile SpA (enthesitis-related arthritis within the JIA umbrella) may precede axial involvement. Early rheumatology involvement is particularly important given the educational, occupational, and psychosocial implications.

When to escalate

Refer or escalate when:

Inflammatory back pain criteria are met with SpA features — rheumatology for diagnostic confirmation and treatment initiation; earlier referral improves outcomes
Acute anterior uveitis — same-day ophthalmology
Bowel symptoms suggestive of IBD in axSpA — gastroenterology with stool calprotectin
Active disease failing two NSAID trials — rheumatology for biologic candidacy assessment
Any fall or spinal trauma in known fused-spine AS — emergency department (CT/MRI full spine)
Acute neurological deficit — emergency department
Pregnancy planning on any DMARD or biologic — rheumatology + obstetrics pre-conception
New aortic regurgitation detected on auscultation — cardiology + echocardiogram
Suspected superimposed septic arthritis (fever, acute joint) — urgent hospital assessment

What this article is and is not

This is general health information drawn from current Australian general practice sources — Therapeutic Guidelines (eTG) Rheumatology, the Australian Living Guideline for Pharmacological Management of Inflammatory Arthritis, ASAS-EULAR 2022 recommendations, AMH biologic monographs, and the RACGP AFP — as well as pivotal international trials. It does not constitute personal medical advice and does not create a doctor–patient relationship. Specific treatment decisions, including biologic candidacy and medication selection, are made with your treating rheumatologist and GP.

For acute eye symptoms: same-day assessment. For general information and peer support: Arthritis Australia, Spondylitis Australia, HealthDirect — Ankylosing spondylitis.

Sources cited

Frequently asked questions

What is inflammatory back pain and how is it different from ordinary back pain?

Inflammatory back pain has a specific pattern — insidious onset before age 40, lasting over three months, with morning stiffness that improves with movement but not rest, and often nocturnal pain waking you in the second half of the night. Ordinary mechanical back pain is typically worse with movement and better with rest. The distinction matters because inflammatory back pain is the primary clinical pointer for axial spondyloarthritis, and its presence signals the need for targeted investigation and rheumatology referral rather than reassurance and analgesia alone.
What tests will my GP order to check for axial spondyloarthritis?

Your GP will likely request HLA-B27 (a genetic marker present in 80–95% of Australians with ankylosing spondylitis), CRP and ESR (inflammation markers — which can be normal even in active disease), and blood tests checking kidney and liver function before medications. X-rays of the sacroiliac joints and lumbar spine are usually first-line imaging. If X-rays are normal but clinical suspicion remains high, MRI of the sacroiliac joints with STIR sequences detects bone marrow oedema — the earliest sign of active sacroiliitis. Rheumatologist referral is typically needed to access Medicare-funded MRI.
What does biologic therapy involve and how is it accessed in Australia?

TNF inhibitors — adalimumab, etanercept, infliximab, golimumab, certolizumab — are PBS-listed for ankylosing spondylitis through the Section 100 Authority programme. Eligibility requires meeting ASAS classification criteria, a BASDAI symptom score of four or more, evidence of active inflammation on blood tests or MRI, and failure of at least two NSAID trials. Biologics are initiated and supervised by a rheumatologist. Before starting, screening for latent tuberculosis, hepatitis B and C, and vaccination update are required. Many patients access biosimilar versions, which are equally effective and routinely available.
Can I exercise with ankylosing spondylitis, and what type is recommended?

Yes — daily exercise is one of the most important long-term strategies for axial spondyloarthritis. Extension-biased spinal exercises counteract the kyphotic posture the disease drives toward; cardiorespiratory fitness reduces cardiovascular risk; and physiotherapy-supervised group programmes are superior to home exercise alone. Aquatic exercise is excellent for low-impact full-range movement, especially during flares. Under a GP Chronic Condition Management Plan, Medicare-subsidised physiotherapy and exercise physiology visits are available. Rest alone is not recommended — movement reduces morning stiffness rather than worsening it.
What warning signs in axSpA should I act on urgently?

The most important is sudden eye pain and redness — anterior uveitis affects about 30% of people with axSpA and requires same-day ophthalmology review to prevent permanent damage. Persistent bowel symptoms (diarrhoea, blood, weight loss) can indicate inflammatory bowel disease, which coexists in about 10% of cases. In people with long-standing fused-spine disease, even a minor fall or bump can cause a serious spinal fracture — treat any spinal trauma as an emergency. New chest pain or a heart murmur warrants cardiovascular evaluation.

Source quality

Sources grouped by evidence tier. AU primary tier first; international where AU is silent or lagging; named-author reconstruction where guidelines have not yet caught up. How tiers work.