Psoriatic arthritis

Psoriatic arthritis is an inflammatory arthritis characterized by a particular type of swelling of the skin (psoriasis) and joints.

Psoriatic arthritis is an inflammatory disorder that occurs when your body’s immune system, which normally fights harmful organisms such as viruses and bacteria, begins to attack healthy cells and tissue. The abnormal immune response causes inflammation in your joints as well as the overproduction of skin cells.

Key Points

  1. Psoriatic arthritis is caused by an abnormal immune response.
  2. Between one and two in every five people with psoriasis will develop psoriatic arthritis.
  3. It usually develops within 10 years of psoriasis being diagnosed, although some people may experience problems with their joints before they notice any symptoms affecting their skin.
  4. The main symptoms include joint pain and swelling, scaly patches on areas of skin and thickening or pitting of the fingernails and toenails.
  5. Management includes medicines and other treatments from your doctor or specialist team, in conjunction with learning about the condition and following lifestyle measures.

Psoriatic arthritis usually starts slowly:

  • Some people develop skin symptoms first while others see joint inflammation first.
  • Joint tissue becomes inflamed leading to pain, swelling and stiffness.
  • Over time, the muscles and ligaments around the bone, the cartilage and the bones themselves, can become inflamed and damaged, often leading to joint deformities.

Men and women are equally affected by symptoms of psoriatic arthritis, which usually appear during adulthood.

Causes

It is not entirely clear why the immune system turns on the body’s own tissues, but it seems likely that both genetic and environmental factors play a role:

  • Many people with psoriatic arthritis have a close relative, such as a parent or sibling, with the disease
  • Researchers have discovered certain gene mutations that appear to be associated with psoriatic arthritis.

Symptoms

Skin symptoms

The skin symptoms of psoriatic arthritis usually appear before the joint symptoms — often years earlier. However, it is possible for both skin and joint symptoms to appear at the same time, or for the joint symptoms to appear first. A diagnosis will be made when both skin and joint symptoms are present and is confirmed by relevant tests.

The most common skin symptoms are:

  • Scaly, silver-grey skin patches, particularly on the elbows, knees, lower back and scalp.
  • Plus pitted, ridged, split or discoloured fingernails and toenails.

Most people with psoriatic arthritis do NOT have severe skin symptoms. If you have severe skin symptoms it does not mean you will have severe joint symptoms. 

Joint symptoms

Any joint can be affected by psoriatic arthritis; sometimes it is just one or two joints, but it can be more.

  • Pain, swelling and stiffness of the joints are the most common problems, often affecting mobility.
  • Swelling of fingers and toes can give a ‘sausage-like’ appearance.
  • In some cases psoriatic arthritis can cause deformity, enlarging the joints.
  • This can make walking painful, and shoes difficult to fit.

Diagnosis

Psoriatic arthritis may take some time to diagnose. Doctors will ask about medical history and conduct a physical examination, assessing skin and joint symptoms. There will be a variety of blood tests and x-rays.

Treatment

People who become active self-managers of their condition tend to be better informed and may experience less pain and disability, often having a better long-term outcome.

A range of health practitioners can provide support and advice:

  • General practitioner — your GP helps coordinate care and arranges referrals to other associated medical professionals
  • Rheumatologist — specialises in diagnosing and treating bone, joint and muscle disorders
  • Physiotherapist — helps with mobility techniques, stretches and exercises that are appropriate to psoriatic arthritis, including ways to help manage pain and daily activities
  • Occupational therapist — evaluates and designs programmes to accomplish basic daily tasks
  • Podiatrist or orthotist — provides professional assessment and management of feet, including supply of such things as shock-absorbing soles for shoes.
  • Support groups are also a valuable resource. People who have similar difficulties can provide empathy and share daily experiences and challenges.

Medications

It's very important to take medications to decrease inflammation and prevent joint damage. Psoriatic arthritis can be managed with a combination of medicines, topical creams and treatments to relieve skin symptoms and joint pain to help you maintain wellbeing.

Although there is no cure, medicine and treatment options have substantially improved in recent years. Those used for psoriatic arthritis fall into the following categories:

Analgesics – pain relievers, such as paracetamol, can help to ease pain, sometimes used in conjunction with other drugs.

NSAIDs (non steroidal anti-inflammatory drugs) – such as ibuprofen, are usually the first medicines prescribed in treatment of psoriatic arthritis. COX-2 inhibitors (eg, celecoxib and meloxicam), fall into this category. NSAIDs can improve pain and stiffness by reducing inflammation.

DMARDs (disease modifying anti-rheumatic drugs) – these are medicines commonly used for rheumatoid arthritis, but may also improve some symptoms of psoriatic arthritis, especially inflammation of arm and leg joints (eg, methotrexate, sulfasalazine). For all DMARDs, routine monitoring of blood counts and liver tests are mandatory and it is very important to immediately report any infection.

Biologic medicines – these are the latest disease-modifying medicines available for treating severe psoriatic arthritis. A number of these medicines target molecules that cause inflammation, called tumour necrosis factor (TNF), reducing symptoms. Biologics that can be used for psoriatic arthritis include etanercept, infliximab and adalimumab.

Corticosteroids (usually prednisone) are powerful anti-inflammatory medicines. These medicines have possible side effects and require careful monitoring of blood pressure, cholesterol, glucose levels and bone density. These drugs can also be injected directly into inflamed joints (‘cortisone’ injections) which reduces the risk of generalised side effects.

Treatment of skin problems

Therapies available to treat your skin can be used alone or in combination. This can include creams, tablets or light therapy.

Topical therapies – these are creams and lotions that you apply directly to your skin and are usually the first treatment used for psoriasis. Some topical therapies require a prescription, but many can be bought over-the-counter at your pharmacy. Topical therapies can make your skin look better and feel more comfortable.

Phototherapy – sometimes also called light therapy; it involves exposure to different types of high-intensity ultraviolet (UVA) light to help improve psoriasis.

Photochemotherapies – this is when medicines are used in conjunction with phototherapy when the psoriasis is severe. These medicines can have serious side effects and will be closely monitored.

Treatment - surgery

Some people find that as skin symptoms get better or worse, joint symptoms do the same at the same time. While not common, surgery is occasionally needed if joint damage has occurred.

  • Operations may vary from minor ones to major surgery, such as hand surgery or joint replacement of the knee or hip.
  • Splints can also be used to support weakened joints to protect them from injury and rest an inflamed joint by stopping it from moving.
  • Splints may also improve the function of a damaged joint.

Self care

With careful management, most activities should be achievable. For the best part, psoriatic arthritis is not a barrier to employment, raising a family, or keeping physically active. However, it affects people differently, so learning about the condition and what can be done, is vital for self-management.

Good posture

This is vital. It is very important to pay attention to how you stand and sit at all times. It is also important to be aware of posture as you move about:

  • When standing, keep bodyweight balanced and even on both feet with shoulders relaxed (back and down).
  • Keep the back of the neck long, allowing the chin to drop slightly forwards.
  • Do not stand still for too long and when moving, try to maintain this tall, relaxed posture.
  • Have a good supportive chair when sitting; it should be firm, upright and allow the feet to touch the floor with knees and hips at right angles.
  • Avoid neck strain if working at a desk or computer by having the screen at eye level.

Sleep

A good night’s sleep is essential for rest and repair of the body.

  • Use a mattress that gives support, but is not too hard, and a pillow which fits snugly under the neck, supporting the head.
  • Sleep in a position that is most comfortable, but if on the side, avoid a lot of bending at the hips and knees.

Exercise

Any physical activity needs to be tailored to fitness level and severity of arthritis. It is important to stretch before and after any exercise and begin with light exercise, building up to more strenuous activity.

Healthy eating

There is very little scientific evidence that diet has an effect on psoriatic arthritis. However, a good balanced diet is important for maintaining your general health.

Being overweight puts unnecessary stress on joints such as hips, knees and the spine. On the other hand, people with psoriatic arthritis often lose their appetite. If this happens to you, try to eat more meals in smaller portions throughout the day. This will help to provide the sustenance you need.

Work choices

Most people are able to continue in their choice of occupation, but during flares, what and how things are done might need to be adapted.

  • If choosing or changing jobs, it is helpful to select one where a range of postures, positions and tasks is possible.
  • An active job, although physically hard at times with psoriatic arthritis, is better than sitting in a chair all day.
  • If a job prevents much movement, compensate by moving more at other times.
  • In some work settings an ergonomic assessment of the physical environment can be done.

Relaxation

Relaxation can help to prevent and reduce excessive levels of tension and anxiety that often accompany psoriatic arthritis. If sleeping is a problem, then it is important to include a dedicated period of relaxation just before bedtime.

Become an expert self-manager

There are some things you can't control, such as getting psoriasis, however there are many things you can. What you do day to day to keep well, learn about your meds, how your body reacts, balance stress, work, sleep, healthy eating and much more does make a BIG difference. Attending a self-management programme is a great way to develop these skills further. 

Learn more

Psoriatic arthritis section NHS Choices
Psoriatic arthritis National Psoriasis Foundation
Images and slideshow Mayo Clinic


 

Credits: Arthritis New Zealand. Reviewed By: Health Navigator Last reviewed: 04 Apr 2015