Psoriatic arthritis is a chronic inflammatory disease of the joints associated with the skin condition psoriasis. It belongs to a subgroup of rheumatic diseases called spondylarthritis (SpA). This is an autoimmune disease, which means that the immune system attacks the body's own tissues, causing inflammation.

Psoriatic arthritis can affect the joints, tendons and entheses (where tendons and ligaments attach to bones). In some people, the disease mainly affects the smaller joints in the hands and feet, while in others it affects the larger joints or the spine. The disease varies between individuals – both in terms of symptoms and severity.

Psoriatic arthritis most often occurs in people with psoriasis, but not everyone with psoriasis develops it. Around 20–30% of people with psoriasis develop psoriatic arthritis, whereas it is estimated that about 0.5% of the general population has the condition.

The disease most often begins between the ages of 30 and 50, but can occur at any age. It is similarly common in men and women. Heredity plays a part, and it is common for more than one person in the same family to have psoriasis or rheumatic diseases.

Symptoms can vary greatly, both between individuals and over time in the same individual. Common symptoms are:

• Pain, swelling and stiffness in the joints, especially in the morning (for more than 30 minutes).
• Fatigue and lack of energy
• Swollen fingers or toes ('sausage finger/sausage toe').
• Pain in tendons and ligaments, e.g. in the heels or elbows.
• Back pain and stiffness if the spine or hips are inflamed.
• Nail defects (holes, cracks or loosening of nails).
• Skin symptoms of psoriasis (red, scaly patches), although they can precede, follow or occur at the same time as joint symptoms.

If the disease is not treated, it can cause permanent joint damage.

• persistent joint pain, swelling or stiffness are present.
• A person with psoriasis develops arthritic symptoms.
• a finger or toe suddenly swells up.
• Back pain and morning stiffness are persistent.

Early diagnosis and treatment are crucial for reducing inflammation, alleviating symptoms and preventing joint damage.

The diagnosis of gout is based on a medical history, physical examination and test results. No single test confirms the condition; rather, a doctor assesses the overall picture.

The analysis is based on, among other things:

• Clinical picture, case history and family history.
• Physical examination of joints, tendons, skin and nails.
• Blood tests to measure inflammation and rheumatism tests to rule out other rheumatic diseases.
• Imaging investigations, such as X-rays, ultrasound or MRI, to assess inflammation and possible joint changes.

If a person with psoriasis develops joint symptoms, the suspicion of psoriatic arthritis increases. Diagnosis is made by a rheumatologist, often in collaboration with a dermatologist.

Early diagnosis is crucial, as timely treatment can reduce symptoms and prevent permanent joint damage.

The aim of treatment is to reduce inflammation, relieve symptoms, protect joints and improve quality of life. Treatment is individualised and depends on the severity of the disease.

Common drug treatments include:

• Anti-inflammatory and painkilling medication for symptoms.
• Steroids in tablet form, or injected into a joint, are used when symptoms worsen and to bridge the gap until disease-modifying drugs begin to have an effect.
• Conventional disease-modifying antirheumatic drugs: methotrexate.
• Biological DMARDs and targeted DMARDs that act on specific components of the immune system.

Many people require concurrent treatment for psoriasis. Treatment is usually overseen by a rheumatologist, often in collaboration with a dermatologist.

Patients can have a significant impact on their well-being through daily routines and supportive therapy:

• Exercise and physiotherapy to maintain skill and strength.
• Balance between stress and rest
• A healthy diet and maintaining body weight
• Avoid smoking
• Stress reduction and plenty of sleep
• Learn about the disease and seek support, e.g. from the Arthritis Society

It is important to be an active participant in your own treatment and to cooperate well with healthcare professionals.

Psoriatic arthritis is a chronic condition, but with modern treatment, many people achieve good control of their symptoms and can live an active and fulfilling life.

The outlook has improved significantly with the advent of biopharmaceuticals. Early diagnosis and appropriate treatment are crucial to prevent permanent joint damage and improve quality of life.