Psoriatic Arthritis

Psoriatic arthritis, often shortened to PsA, is a long-term inflammatory condition that can cause painful, swollen or stiff joints. It can also affect the places where tendons attach to bones, the fingers and toes, and sometimes the spine.

PsA is related to psoriasis, a skin condition that causes patches of inflamed, often scaly skin. Most people with PsA have psoriasis before joint symptoms begin, but joint symptoms can sometimes appear first. The skin changes may be small or hidden on the scalp or other parts of the body.

What happens in psoriatic arthritis?

The immune system causes inflammation in certain joints and tissues. A joint may become swollen, warm, tender and difficult to move. Inflammation can also occur at an enthesis—the place where a tendon or ligament attaches to bone. The heel is one common site.

PsA can affect different parts of the body in different ways. Some people have only a few affected joints, while others have many. Symptoms may come and go or remain active for longer periods.

The exact cause is not known. Genes and other factors contribute to risk, but having psoriasis does not mean that you will definitely develop arthritis. PsA is not contagious, and it is not caused by something you did wrong.

What symptoms should I look for?

PsA may cause:

• Pain, swelling or stiffness in one or more joints
• Stiffness after waking or sitting still, which may ease as you move
• A whole finger or toe becoming swollen—sometimes called a sausage digit
• Pain at the back of the heel or under the foot
• Lower back, buttock or neck pain and stiffness in some people
• Tiredness

The pattern is not the same for everyone. PsA can affect joints on one side or both sides of the body, and the symptoms can change over time.

Persistent joint swelling deserves assessment, even if the skin psoriasis is mild.

What changes can happen to my skin and nails?

Psoriasis may cause dry, scaly or inflamed patches on the elbows, knees, scalp or elsewhere. On darker skin, a patch may look purple, brown or darker than the surrounding skin rather than bright red. Some people have only a small area of psoriasis that is easy to overlook.

The nails may develop tiny dents called pits. They may also become thick, crumbly, discoloured or partly lift from the nail bed. Nail changes can have other causes too, so your clinician will assess them alongside your other symptoms.

Tell your rheumatologist about skin or nail changes, even if they have never caused you much trouble. They can provide useful clues and may affect your treatment plan.

Can PsA affect more than the joints?

Yes. Some people with PsA develop inflammation inside the eye, called uveitis. It may cause a painful red eye, sensitivity to light or blurred vision. These symptoms need urgent assessment by an eye specialist.

Inflammatory bowel disease can occur in some people. Tell your clinician about persistent diarrhoea, blood in the stool or ongoing abdominal symptoms. Your team will also pay attention to general health concerns such as blood pressure, diabetes, cholesterol and weight.

Not every new symptom is caused by PsA. Let your healthcare team know when something changes so it can be assessed properly.

How is psoriatic arthritis diagnosed?

There is no single blood test or scan that confirms PsA. Your clinician will bring together your symptoms, examination and relevant test results.

They may:

• Examine your joints for swelling and tenderness
• Check painful tendon-attachment sites, fingers and toes
• Look at your skin, scalp and nails
• Ask whether you or a family member has psoriasis
• Ask about back pain, eye symptoms and bowel symptoms
• Arrange blood tests or imaging when these would help

X-rays, ultrasound or MRI can sometimes show inflammation or joint changes. Blood tests may help assess inflammation or consider other causes of your symptoms. Normal blood tests do not automatically rule out PsA.

Sometimes a swollen joint needs a fluid sample to check for another cause, such as infection or gout. Your clinician will decide whether this is necessary.

Why does early treatment matter?

Active inflammation can affect cartilage, bone and nearby tissues over time. Treatment aims to reduce pain and swelling, protect the joints and help you continue daily activities. Your rheumatologist will review whether it is working and change the plan if inflammation remains active.

The goal is usually remission—little or no active disease—or the lowest disease activity that can reasonably be achieved. Improving skin symptoms is important too, but skin creams alone do not treat inflammation inside the joints.

There is currently no guaranteed cure for PsA. Many people nevertheless gain good control with treatment.

How is psoriatic arthritis treated?

Your treatment depends on which parts of the body are affected, how active the disease is, and your other health conditions. A person with a few mildly affected joints may need a different plan from someone with persistent joint swelling, extensive psoriasis or spinal symptoms.

Your rheumatologist may work with a dermatologist when skin or nail disease also needs attention.

Medicines for symptom relief

Non-steroidal anti-inflammatory drugs, or NSAIDs, may reduce pain and stiffness. They can help symptoms but may not be enough to control persistent inflammation or prevent damage. NSAIDs are unsuitable for some people, including those with certain stomach, kidney or heart problems. Check before taking them regularly, even if you can buy them without a prescription.

A steroid injection into a particular inflamed joint may sometimes help. Your clinician will decide when it is appropriate. Repeated or prolonged use of steroid tablets is generally avoided where possible because of side effects and the need for better long-term disease control.

Disease-modifying medicines

Disease-modifying antirheumatic drugs, or DMARDs, are used to control persistent inflammatory arthritis. Conventional DMARDs include methotrexate, sulfasalazine and leflunomide. The choice depends on your pattern of arthritis and whether skin disease is also a concern.

These medicines take time to work and often require blood tests or other monitoring. Methotrexate for arthritis is taken once a week, not every day. If it is prescribed for you, make sure you understand your weekly dosing day and folic acid schedule.

Tell your rheumatology team about side effects, infections, pregnancy plans and all other medicines or supplements you take. Do not change a prescribed DMARD without discussing it with your team.

Biologic and targeted medicines

If PsA is more active or conventional treatment has not worked well enough, your rheumatologist may discuss a biologic or targeted medicine. Different medicines act on different pathways involved in inflammation. Some are injections or infusions; others are tablets.

The best choice depends on your joint, spine, skin and nail symptoms, and on conditions such as uveitis or inflammatory bowel disease. A medicine that suits one person may not be the best choice for another. Before certain treatments, you may need infection screening, a vaccination review and ongoing monitoring.

Your rheumatologist will explain the expected benefits and possible risks so you can decide together.

What about treatment for my skin?

Skin treatment may include moisturisers, prescribed creams, light treatment or medicines that work throughout the body. Your dermatologist and rheumatologist can coordinate care when both skin and joint symptoms need treatment.

Tell both teams about every medicine you use. Some treatments can help both psoriasis and arthritis; others mainly help one part of the condition. Do not assume that clear skin means joint inflammation is controlled, or that comfortable joints mean the skin no longer needs care.

What can I do day to day?

Stay active

Regular movement helps maintain strength, joint mobility and general fitness. Walking, cycling, swimming, suitable strength exercises and gentle stretching are possible options. Begin at a manageable level and build up gradually.

If a joint or heel is particularly painful, you may need to adapt the activity for a time. A physiotherapist can help you find exercises that suit your symptoms. An occupational therapist can suggest ways to make work and daily tasks easier.

Pay attention to your feet

Heel pain or foot arthritis can make walking difficult. Supportive footwear or an insole may help some people, but the right choice depends on the cause of pain. Ask your clinician or a relevant foot-care professional before spending money on special inserts.

Look after your general health

If you smoke, ask for help to stop. A balanced diet, regular activity and attention to blood pressure, cholesterol and blood sugar support your overall health. If weight is affecting your health, your team can help you make achievable changes.

There is no single diet that cures PsA. Food and supplements do not replace treatment for active joint inflammation. Check before taking herbal products, which can have side effects or interact with medicines.

Manage fatigue and emotional strain

Pain, poor sleep and fatigue can affect work, relationships and mood. It may help to spread demanding tasks through the day and discuss practical adjustments at home or work. Tell your healthcare team if fatigue remains severe or low mood is affecting you. These concerns are part of your care.

What if I want to become pregnant?

Many people with PsA have healthy pregnancies. Speak to your rheumatologist before trying to conceive, because some medicines need to be stopped or changed in advance while others may be suitable in selected circumstances.

Plan how your arthritis and psoriasis will be managed during pregnancy, after delivery and while breastfeeding. Do not stop treatment without an alternative plan. If you think you may be pregnant while taking a medicine that could be harmful in pregnancy, contact your prescribing team promptly.

How do I recognise a flare?

A flare is a period when symptoms become more active. You may notice increased joint swelling, morning stiffness, heel pain, back symptoms or skin psoriasis. Contact your team if symptoms persist, repeatedly return or interfere with normal activities.

A suddenly very painful, hot, swollen joint, particularly with fever, needs urgent medical assessment. It may be caused by an infection rather than a PsA flare.

When should I seek medical help?

Contact your rheumatology team promptly if:

• A joint remains swollen or your stiffness and pain are worsening.
• A whole finger or toe becomes newly swollen.
• Your current treatment is not helping or is causing side effects.
• You develop new skin, nail, back or persistent bowel symptoms.
• You are planning pregnancy or think you may be pregnant while taking treatment.

Seek urgent eye care for a painful red eye, light sensitivity or blurred vision. Seek urgent medical assessment for a suddenly hot and very painful joint, especially if you also have fever.

Questions worth asking at your next appointment

• Which parts of my body are affected by PsA?
• Is there active joint inflammation, and how will we measure improvement?
• Does my skin or nail disease affect the choice of medicine?
• When should I expect treatment to help?
• What monitoring or vaccinations do I need?
• What should I do if symptoms flare or I develop an infection?
• Which exercises and footwear would suit me?
• Do I need a dermatologist as part of my care?

This information is general. Discuss your diagnosis, medicines and monitoring schedule with your own healthcare team.