Psoriatic Arthritis

Psoriatic arthritis (sorry-attik arth-ry-tus) can cause pain, swelling and stiffness in and around your joints. It usually affects people who already have the skin condition psoriasis (sur-ry-a-sis). This causes patches of red, raised skin, with white and silvery flakes. Sometimes people have arthritis symptoms before the psoriasis. In rare cases, people have psoriatic arthritis and never have any noticeable patches of psoriasis.

Psoriatic arthritis and psoriasis are autoimmune conditions. Our immune system protects us against illness and infection. In autoimmune conditions, the immune system becomes confused and attacks healthy parts of the body. Both conditions can affect people of any age. It’s estimated that around one in five people with psoriasis will develop psoriatic arthritis.

People with psoriasis are as likely as anyone else to get other types of arthritis, such as osteoarthritis or rheumatoid arthritis. These conditions are not linked to psoriasis. Psoriatic arthritis is a type of spondyloarthritis. These are a group of conditions with some similar symptoms.

Psoriatic arthritis can cause a number of symptoms around the body. People will often have two or more of these symptoms, and they can range from mild to severe. One of the main symptoms is pain, swelling and stiffness because of inflammation inside a joint. This is known as inflammatory arthritis. Inflammation is normally a useful tool of a healthy immune system. The body sends fluid, mainly blood, to a part of the body to fight off infection. But when someone has a type of inflammatory arthritis, inflammation can cause pain, swelling and stiffness in joints.

Any joint can be affected in this way. The most commonly affected joints are the:

• neck

• back

• shoulders

• elbows

• wrists

• fingers

• knees

• ankles

• toes.

Joint stiffness is usually worse first thing in the morning, and it can last for more than 30 minutes. You may also feel stiff after you’ve been resting. Psoriatic arthritis can cause connective tissue called entheses (en-thee-seas) to become inflamed. Entheses attach tendons and ligaments to bones. When they become inflamed it’s known as enthesitis.

Enthesitis pain can spread over a wider area rather than just inside a joint. Affected areas can feel tender if you touch them or if there’s just a small amount of pressure on them. It commonly occurs in the feet. This can happen at the back of the heel or on the bottom of the foot near the heel. In some cases, this pain can make standing or walking difficult.

The knees, hips, elbows and chest can also be affected by enthesitis. People with psoriatic arthritis can have swollen fingers or toes. This is known as dactylitis (dak-till-eye-tus), or sausage digit, to describe how whole fingers or toes swell up. It most commonly affects one or two fingers or toes at a time. It can also cause fatigue, which is severe and persistent tiredness that can’t be cured with rest.

There are different types of psoriasis. The most common is chronic plaque psoriasis. This causes patches of red, raised skin, with white and silvery flakes. It can occur anywhere on the skin, but most commonly at the elbows, knees, back, buttocks and scalp. Psoriasis can cause small round dents in finger and toe nails, this is known as pitting. Nails can also change colour, become thicker and the nail may lift away from your finger.

Having psoriatic arthritis can put you at risk of developing other conditions and complications around the body. The chances of getting one of these are rare. But it’s worth knowing about them and talking to your doctor if you have any concerns.

Eyes

Seek urgent medical attention if one or both of your eyes are red and painful, particularly if you have a change in your vision. You could go to your GP, an eye hospital, or your local A&E department. These symptoms could be caused by a condition called uveitis, which is also known as iritis. It involves inflammation at the front of the eye. This can permanently damage your eyesight if left untreated.

Other symptoms are:

• blurred or cloudy vision

• sensitivity to light

• not being able to see things at the side of your field of vision – known as a loss of peripheral vision

• small shapes moving across your field of vision.

These symptoms can come on suddenly, or gradually over a few days. It can affect one or both eyes. It can be treated effectively with steroids.

Heart

Psoriatic arthritis can put you at a slightly higher risk of having a heart condition. You can reduce your risk by:

• not smoking

• staying at a healthy weight

• exercising regularly

• eating a healthy diet, that’s low in fat, sugar and salt

• not drinking too much alcohol.

• These positive lifestyle choices can help to improve your arthritis and skin symptoms.

Talk to your doctor if you have any concerns about your heart health.

Crohn’s disease

Crohn’s disease is a condition in which parts of the digestive system become inflamed. See a doctor if you have any of these symptoms, particularly if you have two or more and they don’t go away:

• blood in your poo

• diarrhoea for more than seven days

• regular pain, aches or cramps in your stomach

• fevers

• a general feeling of being unwell

• unexplained weight loss.

Non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is a term used to describe some conditions where there is a build-up of fat in the liver. This doesn’t cause problems in the early stages. But it can lead to cirrhosis (sir-oh-sis), which is when the liver becomes scarred and may stop working properly.

See a doctor if you have:

• extreme tiredness

• pain in the top right of the tummy, which can be dull or aching

• unexplained weight loss

• yellowing of the skin and eyes, which is known as jaundice

• itchy skin

• swelling in the legs, ankles, feet or tummy.

The genes you inherit from your parents and grandparents can make you more likely to develop psoriatic arthritis. If you have genes that put you at risk of this condition, the following may then trigger it:

• an infection

• an accident or injury

• being overweight

• smoking.

There is also an element of chance, and it might not be possible to say for certain what caused your condition. Psoriasis and psoriatic arthritis are not contagious, so people can’t catch it from one another.

If your GP thinks you have psoriatic arthritis, you’ll need to see a rheumatologist. These are doctors with special knowledge of the condition.

There’s no specific test to diagnose psoriatic arthritis, so a diagnosis will be made based on your symptoms and a physical examination by your doctor. Tell your doctor if you have any history of psoriasis or psoriatic arthritis in your family.

If you’ve developed psoriasis in the past few years, and symptoms of arthritis have started more recently, this could suggest it’s psoriatic arthritis. But it doesn’t always follow this pattern. It can sometimes be difficult to tell the difference between psoriatic arthritis and some other conditions, including rheumatoid arthritis, osteoarthritis and gout.

Blood tests such as those for rheumatoid factor and the anti-CCP antibody can help. People with psoriatic arthritis tend not to have these antibodies in their blood. People who have rheumatoid arthritis are more likely to test positive for them – especially if they’ve had rheumatoid arthritis for a while. These tests won’t say for certain if someone has psoriatic arthritis, but they can help when taking everything else into account.

X-rays of your back, hands and feet may help because psoriatic arthritis can affect these parts of the body in a different way to other conditions. Other types of imaging, such as ultrasound scans and magnetic resonance imaging (MRI), may help to confirm the diagnosis.

Because there are several features of psoriatic arthritis, there are different treatment options. Some of these are just for symptoms, such as pain and swelling, while some can treat the condition itself and reduce its symptoms. People react differently to specific treatments, so you may need to try a few options to find what works for you.

Types of treatments

For the arthritis:

• non-steroidal anti-inflammatory drugs (NSAIDs)

• steroid injections into affected joints

• disease modifying anti-rheumatic drugs (DMARDs)

• biological therapies.

For the psoriasis:

• creams and ointments

• retinoid tablets

• ultraviolet light therapy, also known as phototherapy

• some DMARDs and biological therapies used for arthritis can also help the psoriasis.

Treatments for the arthritis

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs can reduce pain and stiffness, but they might not be enough to treat symptoms of psoriatic arthritis for everyone. Some people find that NSAIDs work well at first but become less effective after a few weeks. If this happens, it might help to try a different NSAID.

There are about 20 available, including:

• ibuprofen

• etoricoxib

• etodolac

• naproxen

Like all drugs, NSAIDs can have side effects. Your doctor will reduce the risk of these, by prescribing the lowest effective dose for the shortest possible period of time.

NSAIDs can sometimes cause digestive problems, such as stomach upsets, indigestion or damage to the lining of the stomach. You should also be prescribed a drug called a proton pump inhibitor (PPI), such as omeprazole or lansoprazole, to help protect the stomach.

For some people, NSAIDs can increase the risk of heart attacks or strokes. Although this increased risk is small, your doctor will be cautious about prescribing NSAIDs if there are other factors that may increase your overall risk, for example, smoking, circulation problems, high blood pressure, high cholesterol or diabetes.

Some people have found that taking NSAIDs made their psoriasis worse. Tell your doctor if this happens to you.

Steroid treatment

Steroid injections into a joint can reduce pain and swelling, but the effects do wear off.

Having too many steroid injections into the same joint can cause some damage to the surrounding area, so your doctor will be careful not to give you too many.

Steroid tablets or a steroid injection into a muscle can be useful if lots of joints are painful and swollen. But there’s a risk that psoriasis can get worse when these types of steroid treatments wear off.

If used over the long term, steroid tablets can cause side effects, such as weight gain and osteoporosis (oss-tee-o-pur-oh-sis). This is a condition that can weaken bones and cause them to break more easily.

Disease-modifying anti-rheumatic drugs (DMARDs)

There are drugs that can slow your condition down and reduce the amount of inflammation it causes. This in turn can help prevent damage to your joints. These are called disease-modifying anti-rheumatic drugs (DMARDs) (dee-mards). Many DMARDs will treat both psoriasis and psoriatic arthritis.

Because they treat the cause of your condition rather than the symptoms, it can take several weeks or even up to three months before you feel an effect. You’ll need to keep taking them even if they don’t seem to be working at first. It’s also important to keep taking them once they do take effect. People will usually take DMARDs for many years, sometimes all their life.

The decision to use a DMARD, and which one, will depend on several factors, including what your symptoms are like and the likelihood of joint damage. You may need to take more than one DMARD at a time. You can take NSAIDs and painkillers at the same time as DMARDs.

Like all drugs, DMARDs can have some side effects. But it’s important to remember that not treating psoriatic arthritis effectively could lead to permanent bone and joint damage.

When taking a DMARD you’ll need regular blood tests, blood pressure checks, and in some cases a urine test. These tests allow your doctor to monitor the effects of the drug on your condition but also check for possible side effects.

There are different groups of DMARDs and they work slightly differently. DMARDs are normally taken as tablets you swallow, though methotrexate can be injected too. They reduce the activity of the immune system.

The following DMARDs can be used at early stage after diagnosis:

• methotrexate

• sulfasalazine

• leflunomide

You may be able to try some newer DMARDs, if other treatments haven’t worked.

These newer DMARDs work on specific parts of the immune system to reduce inflammation. They’re taken as tablets you swallow.

The following can treat psoriatic arthritis:

• apremilast

• tofacitinib

Both drugs may be prescribed alongside methotrexate

Biological therapies

Biological therapies are drugs that target key parts of the immune system to reduce inflammation. You might be able to try them if other drugs haven’t worked for you.

Two groups of biological therapies are used to treat psoriatic arthritis – anti-TNF drugs and interleukin inhibitors. Anti-TNF drugs target a protein called tumour necrosis factor (TNF). Interleukin inhibitors target interleukin proteins.

The body’s immune system produces both TNF and interleukin proteins to act as messenger cells to help create inflammation. Blocking TNF or interleukin messengers can reduce inflammation and prevent damage to the body.

A biological therapy may be prescribed on its own, or at the same time as a DMARD, such as methotrexate.

The following anti-TNF drugs can treat psoriatic arthritis:

• adalimumab

• infliximab

• etanercept

• golimumab

• certolizumab pegol

The following interleukin inhibitors can treat psoriatic arthritis:

• ustekinumab

• secukinumab

• ixekizumab

Biological therapies can take up to three months to fully take effect.

Treatments for the arthritis

If your psoriasis is affecting your quality of life, or your treatment is not working, you may be referred to a dermatologist. There are a number of treatment options for psoriasis.

Ointments, creams and gels that can be applied to the skin include:

• ointments made from a medicine called dithranol

• steroid-based creams and lotions

• vitamin D-like ointments such as calcipotriol and tacalcitol

• vitamin A-like (retinoid) gels such as tazarotene

• salicylic acid

• tar-based ointments.

For more information about the benefits and disadvantages of any of these talk to your GP, dermatologist or pharmacist.

If the creams and ointments don’t help, your doctor may suggest light therapy, also known as phototherapy. This involves being exposed to short spells of high-intensity ultraviolet light in hospital.

Once this treatment has started, you’ll need to have it regularly and stick to the appointments you’ve been given, for it to be successful. This treatment is not suitable for people at high risk of skin cancer or for children. For some people, this treatment can make their psoriasis worse.

Retinoid tablets, such as acitretin, are made from substances related to vitamin A. These can be useful if your psoriasis isn’t responding to other treatments. However, they can cause dry skin and you may not be able to take them if you have diabetes.

Some DMARDs used for psoriatic arthritis will also help with psoriasis.

1. Moll and Wright 1973

2. CASPAR criteria

3. ASAS Classification Criteria for Peripheral SpA

4. Minimal Disease activity ( MDA)

A patient is classified as achieving MDA when meeting 5 of the 7 following criteria: 6

• Tender joint count ≤ 1

• Swollen joint count ≤ 1

• Psoriasis Activity and Severity Index ≤ 1 or body surface area ≤ 3%

• Patient pain visual analogue score (VAS) ≤ 15

• Patient global disease activity VAS ≤ 20

• Health assessment questionnaire ≤ 0.5

• Tender entheseal points ≤ 1

Disease severity:

1. American College of Rheumatology 20% improvement criteria (ACR20)

2. Psoriatic Arthritis Response Criteria (PsARC)

It is used to assess response to treatment especially after 12 weeks of biologics. Assessment is with the 5 point Likert scale.

a. Patients self assessment

b. Physician’s Global Assessment (PGA)

Considering all the ways the arthritis affects your patient, how is your patient feeling today.

3. Psoriasis Area and Severity Index (PASI)

https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/Rebranded_Content_/Outside%20In%20PASI%20Online.pdf

4. Radiographic measures:

Modified Total Sharp score (mTSS)

5. Quality of life

• Health assessment questionnaire (HAQ)

• Short form 36 (SF-36)

• Dermatology life quality index (DLQI) https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/Rebranded_Content_/Outside%20In%20DLQI%20Online%20use.pdf

6. Cardiovascular disease https://www.nice.org.uk/guidance/cg181

7. PEST https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/Rebranded_Content_/pest_no_logo.pdf

Assessments of PsA:

(Example of PsA assessments whilst my training in the UK)

https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/PsA%20Training%20Manual.pdf

1. 1. 66/68 Joint count

https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/Rebranded_Content_/Joint%20Count%20and%20PsARC.pdf

2. Leeds enthesitis index

https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/OutsideInMaterials/Outside_In_2018_Enthesitis_Scoring_Sheet_v5.pdf

3. NAPSI score

4. BASDAI

https://www.psoriatic-arthritis.co.uk/Assets/Files/Content/Rebranded_Content_/BASDAI_Sheet.pdf