In short
Psoriatic arthritis (PsA) is an inflammatory arthritis that affects the joints, skin and nails, usually in people who have psoriasis. Tell-tale signs are a swollen ‘sausage’ finger or toe and pitted nails. Early treatment protects the joints, and modern medicines often clear skin and joints together.
On this page
What is psoriatic arthritis?
PsA is an immune-driven condition that inflames the joints, the points where tendons attach to bone, and often the skin and nails. It develops in some people with psoriasis — the red, scaly skin condition — though joint pain occasionally comes first.
Some people have mild, occasional symptoms; others need closer care.
What are the symptoms of PsA?
- Joint pain and swelling Fingers, toes, knees or lower back.
- Sausage fingers or toes A whole digit swells up (GlossaryDactylitisSwelling of a whole finger or toe, giving it a ‘sausage’ look — a hallmark of psoriatic arthritis.All terms A–Z).
- Nail changes Pitting, ridges, thickening or nails lifting.
- Heel and sole pain Where tendons attach to bone (GlossaryEnthesitisInflammation where a tendon or ligament attaches to bone, often at the heel or the sole of the foot.All terms A–Z).
- Psoriasis Red, scaly patches before, during or after joint pain.
- Stiffness and fatigue Worse after rest, easing with movement.
How is PsA diagnosed?
There is no single test — the diagnosis is mostly made in clinic:
- Examination Your joints, skin and nails, and any family history of psoriasis.
- Blood tests Mainly to rule out RA and gout; RF and anti-CCP are usually negative in PsA.
- Imaging X-ray, ultrasound or MRI spot joint damage and enthesitis early.
- GlossaryCASPAR criteriaThe checklist doctors use to confirm psoriatic arthritis, combining skin, nail, joint and blood-test findings.All terms A–Z Doctors combine these findings to confirm it.
How is PsA treated?
- Anti-inflammatories NSAIDs for mild joint pain and swelling.
- GlossaryDMARDsDisease-modifying antirheumatic drugs: medicines that calm the disease process itself, not just the symptoms. Methotrexate is the best known.All terms A–Z Calm the immune response behind both joint and skin symptoms.
- GlossaryBiologicsTargeted medicines that block one specific part of the immune response driving inflammation.All terms A–Z TNF, IL-17 or IL-23 blockers — often very effective for skin and joints together.
- Skin treatments Creams and ointments for psoriasis patches.
- Physiotherapy Keeps joints mobile and strong.
What is the outlook?
- Many people reach low disease activity or remission with early, steady treatment.
- PsA can damage joints even when symptoms feel mild, so keep up with treatment.
- Stress, infection or skin irritation can trigger flares; your plan can be adjusted.
- A healthy weight eases joint strain and may help treatment work better.
At a glance
Read the text of this sheet
Psoriatic arthritis is a long-term inflammatory condition affecting the skin and joints, usually in people with psoriasis. Psoriasis causes red, scaly skin patches with silvery scales, often on the elbows, knees, scalp or nails. Nail changes include pitting, ridging, discolouration, thickening or separation. Arthritis causes pain, swelling and stiffness, especially in the fingers, toes and spine. Commonly affected areas: skin, hands and feet, nails, the spine in some cases, and other joints such as knees and elbows.
Questions patients ask
Can I have psoriatic arthritis without psoriasis?
It is uncommon but possible. Joint symptoms sometimes appear before any skin changes, especially if psoriasis runs in the family.
Is psoriatic arthritis hereditary?
Genes play a part — a close relative with psoriasis or PsA raises your risk — but it is not directly inherited. Infections or a joint injury can also act as triggers.
Is there a cure for PsA?
Not yet, but with early treatment many people keep both skin and joint symptoms minimal for long periods.
Is psoriatic arthritis contagious?
No. Neither PsA nor psoriasis can spread from person to person.
Words worth knowing
Full glossary- Biologics
- Targeted medicines that block one specific part of the immune response driving inflammation.
- CASPAR criteria
- The checklist doctors use to confirm psoriatic arthritis, combining skin, nail, joint and blood-test findings.
- DMARDs
- Disease-modifying antirheumatic drugs: medicines that calm the disease process itself, not just the symptoms. Methotrexate is the best known.
- Dactylitis
- Swelling of a whole finger or toe, giving it a ‘sausage’ look — a hallmark of psoriatic arthritis.
- Enthesitis
- Inflammation where a tendon or ligament attaches to bone, often at the heel or the sole of the foot.
This page is intended for general patient education and does not replace personalized medical advice. Please consult your rheumatologist about your specific symptoms, diagnosis, or treatment plan. Last updated 3 October 2026.