Psoriatic Arthritis
About 1 in 5 people with psoriasis also get inflammation in their joints, tendons or spine. It usually starts years after the skin, but sometimes before. Joint damage can begin early, so the clues are worth knowing, and modern treatment works well.
The clues
- Sausage finger or toe: a whole digit swells up (dactylitis)
- Heel or sole pain: where tendons attach to bone, such as the Achilles (enthesitis)
- Morning stiffness lasting more than 30 minutes, easing as you move
- Swollen, warm joints, often a few on one side, including the end finger joints
- Back or buttock pain that’s worse after rest and better with exercise
- Nail changes (pits, lifting) and scalp or buttock-crease psoriasis raise the risk
See your GP within a few weeks if you have psoriasis and new joint swelling, a sausage digit or morning stiffness. In one study, waiting more than 6 months for a diagnosis led to more joint damage and worse function.
Your joints don’t care that your skin is “only mild”. Skin severity barely predicts who gets arthritis.
Tests
- There’s no single blood test: diagnosis is mostly the story and examination
- Blood tests (CRP, ESR) can be normal even with active arthritis
- Rheumatoid factor is usually negative, which helps tell it from rheumatoid arthritis
- X-rays or ultrasound show joint and tendon inflammation or damage
- A yearly 5-question screen (PEST) helps GPs and dermatologists pick it up early
What helps
Treatment is stepped up until the inflammation is quiet. Most people need a rheumatologist.
- Step 1 · EveryoneKeep moving, lose weight if needed, stop smokingExercise eases stiffness. Weight loss improves how well medicines work.
- Works
- Weight loss of 5–10% improves joint scores in trials
- Cost
- Free
- How long
- Ongoing
- Watch for
The best joint supplement is a walk.
- Step 2 · GPAnti-inflammatory tablets (NSAIDs) or a steroid injection into a jointSettles pain and swelling while waiting for a specialist.
- Works
- Good for symptoms; doesn’t prevent damage
- Cost
- $10–25
- How long
- Short term
- Watch for
- Stomach, kidneys and blood pressure with long use.
- Step 3 · RheumatologistMethotrexate, leflunomide or sulfasalazineStandard disease-modifying tablets (DMARDs). Methotrexate also helps the skin.
- Works
- Help many people with joint swelling
- Cost
- PBS: $25 or $7.70 concession
- How long
- Takes 8–12 weeks to work
- Watch for
- Regular blood tests; no alcohol binges on methotrexate; avoid pregnancy.
- Step 4 · RheumatologistBiologic injections or JAK inhibitor tabletsTarget TNF, IL-17 or IL-23 (e.g. adalimumab, secukinumab, guselkumab), or tablets such as upadacitinib. They also clear skin.
- Works
- Around half to two-thirds of people get at least a 50% improvement in joint symptoms
- Cost
- PBS for people who meet criteria, including trying standard medicines first
- How long
- Weeks to months; ongoing
- Watch for
- Infections; TB and hepatitis checks first; some aren’t suitable with bowel disease or heart risks.
Expensive molecules, cheap co-payment. The PBS is doing the heavy lifting.
Costs are rough Australian prices and vary by pharmacy and provider. PBS co-payment: $25, or $7.70 with a concession card. Results are typical figures from trials, not promises.
Look after your heart too
- Psoriatic disease raises the risk of heart disease, diabetes and fatty liver
- Ask your GP for a yearly check: blood pressure, cholesterol, sugar and weight
- Low mood is common with any long-term inflammatory disease: say so if it’s happening
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Gluten-free diet without coeliac diseaseOnly helps if you test positive for coeliac antibodies.
- Turmeric, fish oil or collagen as treatmentSmall or no benefit in trials. Fine as food, not as a substitute for a DMARD.
- “Alkaline” or detox dietsDon’t change joint inflammation.
- Waiting it outPsoriatic arthritis doesn’t usually burn out on its own, and damage is permanent.
If a supplement could switch off IL-17, it would cost $2,000 a month and need a script.
Common questions
How common is psoriatic arthritis?
About 1 in 5 people with psoriasis develop it, usually years after the skin started, but sometimes before.
What are the early signs of psoriatic arthritis?
A swollen sausage-like finger or toe, heel or sole pain, morning stiffness over 30 minutes, swollen joints, or back pain that eases with movement.
Is there a blood test for psoriatic arthritis?
No single test. Diagnosis is based on symptoms and examination, sometimes with X-rays or ultrasound. Blood markers of inflammation can be normal.
Can psoriatic arthritis be cured?
Not cured, but treatment can switch off the inflammation and prevent joint damage. Many people reach low or no disease activity on modern medicines.
Helpful resources
- Psoriasis AustraliaPatient support and information. Free.
- Arthritis AustraliaInformation on psoriatic arthritis and living with it. Free.
- Australasian College of Dermatologists: A–Z of skinDermatologist-written patient information. Free.
Evidence and more information
- Gossec L et al. EULAR recommendations for psoriatic arthritis: 2023 update (Ann Rheum Dis 2024)
- Soriano ER et al. GRAPPA 2021 treatment recommendations for psoriatic arthritis (J Rheumatol 2023)
- Alinaghi F et al. Prevalence of psoriatic arthritis in psoriasis: meta-analysis (JAAD 2019)
- Haroon M et al. Diagnostic delay of more than 6 months worsens outcome in psoriatic arthritis (Ann Rheum Dis 2015)
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