Psoriatic arthritis

This is a form of arthritis that often develops in people with psoriasis. Psoriasis is a common skin condition which is characterised by hard, red scaly patches of skin which occur on the elbows and knees.

Psoriatic arthritis results in pain and inflammation in the joints which can also affect the tendons and ligaments. It ranges in severity from mild through to chronic which may result in a disability. This can affect quality of life.

People with psoriatic arthritis are a greater risk of other conditions such as heart disease. If you develop this form of arthritis then it is important to review your lifestyle and make changes if necessary which will reduce this risk.

There is no cure for psoriatic arthritis but there are treatments available which ease the pain and inflammation as well as reducing the risk of permanent damage and a disability.

Psoriatic arthritis is discussed in the following order:

• Who is most likely to develop psoriatic arthritis?
• How does psoriatic arthritis occur?
• Causes of psoriatic arthritis
• Symptoms of psoriatic arthritis
• Diagnosis of psoriatic arthritis
• Tests for psoriatic arthritis
• Treatment for psoriatic arthritis
• Managing psoriatic arthritis

Who is most likely to develop psoriatic arthritis?

It tends to develop in people with psoriasis. So if 2 out of 100 people develop psoriasis then about 1 in 10 of these will get reactive arthritis.

(Source: Patient UK/Psoriatic Arthritis)

But there are some people who develop reactive arthritis before psoriasis. Then there are others who develop reactive arthritis but never develop psoriasis.

So it can be difficult to say who will get it and who will not.

It usually occurs in adults especially those aged between 25 and 50. But this and psoriasis can affect any age group which also includes children.

If you have psoriasis then you have the same likelihood as other people of developing osteoarthritis or rheumatoid arthritis – the two most common forms of arthritis.

How does psoriatic arthritis occur?

We know that some people with psoriasis will also develop psoriatic arthritis although this does not apply to very psoriasis sufferer. But if it does occur then it causes inflammation, pain and stiffness in the joints, in particular the heels, fingers and toes.

The tendons may also be affected.

Causes of psoriatic arthritis

It is difficult to pinpoint an exact cause for this which is usually the case with many forms of arthritis. Experts suspect that the immune system is involved to a certain extent which may cause to become overactive and attack the tissues and joints of the body.

This appears to be the case in people who are genetically predisposed towards this arthritis. So if you have a family history of psoriatic arthritis and/or psoriasis then this increases your risk of developing this condition.

This includes people with the gene marker HLA-B27 which predisposes them to forms of arthritis such as psoriatic, reactive etc.

However this is not as straightforward at it seems.

There may be other factors to take into account such as a virus, accident or injury or something in the environment which triggers the immune system to respond in this way. But whatever it is it results in a painful and limiting condition.

Symptoms of psoriatic arthritis

These include pain, stiffness and inflammation of the joints. They become red and swollen which is a sign of inflammation which in some cases, can lead to damage in these joints.

The tendons are also affected. A common example of this is where an inflammation develops in the tendons in the fingers or toes which causes them to have a ‘sausage-like’ appearance. This may spread to the ligaments as well. Some joints are more commonly affected than others. But psoriatic arthritis can occur in almost any joint. These include the fingers, toes and the back of the heel plus the wrists, elbows, knees and shoulders. Pain and stiffness in the neck or base of the spine is also included.

The nails on the hands become thicker and tiny depressions (hollows) appear. This may cause the nails to become detached from the nailbed.

Other lesser known symptoms include inflammation in the eyes, e.g. conjunctivitis or iritis. These result in sore, red itchy eyes which weep when exposed to a bright light or change in the environment.

Fatigue and anaemia are not uncommon.

What often happens is that people with psoriasis notice that when this worsens so does their arthritis. Conversely, if their psoriasis improves then their arthritis does at the same time.

The symptoms which affect the joints follow a pattern: this means that they develop in a particular way and range from mild through to severe. Most sufferers fall into a pattern, for example psoriatic arthritis in a large joint such as the knee and a few smaller joints in the fingers or toes.

Diagnosis of psoriatic arthritis

Psoriatic arthritis is diagnosed using a combination of methods which include a physical examination, blood tests, questions about the symptoms and X-rays/MRI scan if applicable.

This applies to many forms of arthritis.

Your GP will start off by asking you about the symptoms of your condition, such as when did they start; is the arthritis painful first thing in the mornings and which joints are affected. He/she will also ask you about your medical history and very importantly, your family history.

He or she will ask you if your parents or if a close family member has this arthritis. There is a genetic link with psoriatic arthritis and if you have inherited this gene then statistically, you are more than likely to develop this condition.

This is followed by the GP examining the joints and other areas of the body which have been affected.

Tests for psoriatic arthritis

You will be referred for tests such as X-rays and blood tests. An X-ray will show the joints affected by this arthritis which have a different appearance to those affected by osteoarthritis or rheumatoid arthritis.

Blood tests are important in that they can detect the presence of antibodies which are known causes of conditions such as these. High levels of an antibody indicate that there is inflammation in the body and what type.

A blood test is also useful at ruling out other types of arthritis such as rheumatoid arthritis. People with this condition have a particular antibody called ‘rheumatoid factor’ in their blood which confirms this form of arthritis. Rheumatoid factor does not usually appear in the blood of people with psoriatic arthritis.

The results of the tests will determine what treatment you have.

Treatment for psoriatic arthritis

Treatment involves a combination of drugs, diet and exercise and physiotherapy. This also includes a few ‘self help’ steps which you can do to ease the symptoms and live as normal as live as possible.

Your treatment plan aims to:

• Ease pain, stiffness and inflammation in your joints
• Prevent joint damage
• Reduce the risk of disability

Pain relief

Painkillers such as non-steroidal anti-inflammatory drugs –also known as ‘NSAID’s’ - are prescribed to relieve pain and stiffness in your joints. These are an effective form of medication and include Ibuprofen, Naproxen and Diclofenac.

A note of warning: if you suffer from psoriasis then be careful taking NSAID’s as they can worsen your skin condition. If you notice this after taking a painkiller then see your GP who will prescribe an alternative.

Another type of painkiller is Paracetamol or Codeine which is useful as a form of pain relief but is not an anti-inflammatory drug.

Corticosteroids or ‘steroids’ for short are useful at easing any inflammation. These can be injected into the affected joint or ingested as a tablet.

Prevent joint damage

There are drugs known as ‘Disease modifying anti rheumatic drugs’or ‘DMARD’s’which are often prescribed soon after a diagnosis of psoriatic arthritis has been confirmed. These drugs dampen down any inflammation with the aim of preventing damage to the joints.

They block the actions of chemicals which are responsible for this inflammation but it will be several months before you notice any effects.

Examples of these drugs are Sulfasalazine and Methotrexate.

There is a new group of drugs which neutralise the effects of a chemical called ‘TNF-alpha’which helps to cause pain and inflammation in the joints. Blocking these will reduce the symptoms and the risk of any damage.

Reduce disability

The third part of your treatment is minimising the risk of a disability which in some situations, can be permanent. This is basically, making a few lifestyle changes so that you remain mobile and independent as possible.

Swimming is a good form of exercise which will not only keep you fit but will tone your muscles without putting pressure on your joints. Walking is another good form of exercise but check with your GP first especially if you have not exercised for a long time.

Physiotherapy is another option and is useful at suggesting ways of staying mobile without risking your joints.

Splints for your wrist or hands can help to protect these against further damage.

Skin treatment

If you have psoriasis as well as arthritis then there are steroid creams, ointments and Vitamin A gels which are useful at treating this skin rash.

You may find that your treatment for arthritis also helps your psoriasis and vice versa.

We have included a section in this guide which discusses these treatments in more detail. Find out more in our treatment for arthritis section.

Managing psoriatic arthritis

This refers to ‘self help’ actions which we have briefly mentioned in the Treatment section above.

Many forms of arthritis require you to make adaptations in your lifestyle and daily routine which include employment, sexual relationships and pregnancy.

This means moving around as much as possible to stop the joints from stiffening up. Take up some form of exercise such as swimming which will benefit your health as well as your joints. Plus it helps to keep your muscles supple and toned which is vital as these will weaken if not used.

If you have problems gripping or picking up objects then an occupational therapist can help. He or she will advise you about aids and ways of adapting areas of your home to make it easier for you.

Maintain a healthy weight. It is important to avoid putting on weight as excess fat will put a strain on your joints which increases the risk of any damage. Plus it causes problems for your heart and other areas of your body.

If your arthritis causes you problems at work then there is help available from a Disability Employment Adviser via your local jobcentre. Your employer may be able to arrange for adaptations to be made to your workstation or advise you in other ways.

If you are looking to have children then discuss this first with your GP. Some forms of medication prescribed for psoriatic arthritis are not recommended during pregnancy so you need to mention this to your GP before he/she arranges your treatment.

For further information visit our living with arthritis section.