I have psoriasis and now my knee is swollen. Is that psoriatic arthritis?

How psoriasis links to the knee

Psoriatic arthritis is an immune-driven inflammation of the joints and of the places where tendons and ligaments attach to bone. It often affects only a few joints at first and not necessarily both sides equally, so one knee can swell while the other is normal.

The severity of the skin does not predict the joints. Some people with mild psoriasis, or only scalp or nail changes, develop significant arthritis.

Signs that point to psoriatic arthritis

• A swollen, warm knee without a clear injury
• Morning stiffness that eases with movement
• Pain at the heel, the back of the ankle or below the kneecap where tendons attach
• A whole finger or toe swelling like a sausage
• Pitted, thickened or lifting nails
• Lower back or buttock stiffness

How it is diagnosed

There is no single blood test for psoriatic arthritis, so the diagnosis rests on the history, examination and the exclusion of other causes. Drawing fluid from the knee rules out infection and gout. Blood tests check inflammation markers and help exclude rheumatoid arthritis. Ultrasound or MRI can show inflamed joint lining and tendon attachments, and X-rays help assess any damage.

Treatment and the role of a knee surgeon

Medical treatment is led by a rheumatologist and ranges from anti-inflammatory medicines to disease-modifying and biologic drugs, which can control both skin and joints. A steroid injection into the knee may settle a single flare once infection is ruled out. Physiotherapy keeps the thigh muscles strong and the knee moving.

A knee surgeon becomes involved when swelling persists despite treatment, when there is mechanical damage such as a meniscus tear, or when later joint wear needs surgery. At Aman Hospital in Doha, Dr. Gelber examines the knee, arranges tests and works alongside your rheumatologist and dermatologist.