Private psoriatic arthritis clinic in London, same-day GP.

The five patterns

• Asymmetrical oligoarthritis — a few joints, often on one side. The commonest pattern.
• Symmetrical polyarthritis — resembling rheumatoid arthritis.
• Distal interphalangeal — the end finger joints, closest to the nails, often with nail changes in the same digit.
• Spondylitis — inflammatory back and sacroiliac pain, with morning stiffness over 30 minutes.
• Arthritis mutilans — rare, severely destructive, and the reason early treatment matters.

If you have psoriasis

• Report any joint pain, swelling or stiffness — particularly morning stiffness lasting over 30 minutes
• Report heel pain, and pain at tendon attachments
• Report back pain that improves with movement and wakes you at night
• Skin severity does not predict joint severity — mild psoriasis can accompany severe arthritis, and scalp, nail and skin-fold psoriasis are particularly associated
• In around 15% of people, the arthritis comes first and the skin follows later

Diagnosis

Clinical, supported by examination of skin, nails, joints and entheses. Rheumatoid factor and anti-CCP are usually negative, which helps distinguish it from rheumatoid arthritis, and inflammatory markers are normal in a substantial minority — so normal blood tests do not exclude it. Ultrasound detects synovitis and enthesitis sensitively; X-rays show established change; MRI is used for spinal involvement.

Treatment

• Anti-inflammatories for mild joint symptoms.
• Steroid injections into individual joints or entheses. Oral steroids are used cautiously, as reducing them can flare the skin badly.
• DMARDs — methotrexate, sulfasalazine or leflunomide — for peripheral joint disease. These do not help spinal disease.
• Biologics and targeted therapies — anti-TNF, IL-17 and IL-23 inhibitors, and JAK inhibitors. These treat skin and joints together and have transformed outcomes.
• Physiotherapy and exercise, which maintain function and are particularly important with spinal involvement.

The rest of the picture

Psoriatic disease carries raised cardiovascular risk, and higher rates of metabolic syndrome, fatty liver, inflammatory bowel disease, depression and uveitis. Annual review of blood pressure, lipids, glucose and weight is part of proper care. Stopping smoking and losing excess weight both improve treatment response measurably.