What is psoriatic arthritis?
Psoriatic arthritis is an inflammatory type of arthritis that usually occurs in combination with psoriasis – a skin disease, which causes thick, red patches with silvery scales to appear on the skin. Hence, psoriatic arthritis typically manifests itself in the skin lesions, which are present in individuals with psoriasis and the joint pain common for arthritis.
What is the connection between psoriasis and psoriatic arthritis?
Both conditions are autoimmune conditions, meaning that a malfunction of the immune system lies at their core. Experts estimate that up to 30% of individuals with psoriasis also develop psoriatic arthritis. Merely about 15% are affected by psoriatic arthritis without any prior skin disease history. While 2 - 3% of the worldwide population has psoriasis, psoriatic arthritis is less common, affecting approximately 24 in 10,000 individuals. So far, however, it remains unclear as to why some people with psoriasis develop psoriatic arthritis, whilst others don’t.
Interestingly, there is no significant relationship between the severity of your psoriasis and your psoriatic arthritis. This means that you may experience more severe forms of psoriasis lesions on your skin, but only observe mild signs of psoriatic arthritis and vice versa. Moreover, the symptoms of psoriasis and psoriatic arthritis do not necessarily occur at the same time.
When does psoriatic arthritis develop?
Typically, the joint problems associated with the condition develop within 10 - 20 years after the initial occurrence of psoriasis on the skin. While psoriasis mainly sets in during adolescence or early adulthood, the peak time for the onset of psoriatic arthritis lays between 30 and 50 years. However, some may already experience signs of psoriatic arthritis before seeing symptoms of psoriasis. In rare cases, psoriatic arthritis may also develop without any changes to the skin.
What are the symptoms of psoriatic arthritis?
If you have been diagnosed with psoriasis and notice any of the following symptoms, you are advised to contact your doctor as soon as possible. An early diagnosis can help reduce the severity of experienced symptoms.
The most frequent symptoms include:
- Swollen and aching fingers and/or toes (causing a “sausage-like” appearance)
- Swelling and pain in knees, ankles and/or wrists
- Pain in the lower back, upper back and neck
- Tenderness and pain over tendons
- General fatigue
- Morning stiffness
- Reduced movement in the joints
- Changes to the toe nails and/or finger nails: pitting, discolouration, separation of the nail from the nail bed
- Eye redness and pain of the eye
- Patches of red, scaly skin with silvery flakes (known as plaques) on the elbows, knees, scalp, and/or the lower end of the backbone
What causes psoriatic arthritis?
It is not yet fully understood how inflammation is caused in psoriatic arthritis. Experts suggest that it is a result of a combination of immunological, genetic and environmental factors.
- Immune dysfunction: As with psoriasis, the affected individuals are impacted by a malfunctioning immune system: In the case of psoriasis, it erroneously attacks the healthy skin of the affected individuals. Similarly, this immune dysfunction mistakenly attacks the joints of people affected by psoriatic arthritis. This consequently induces inflammation in the joints and ultimately causes aforementioned stiffness, pain and swelling. So-called T lymphocytes – a certain type of cell in the immune system – play a critical part in this process. While they usually monitor the blood stream for infections and cancer, they have been found in great numbers in inflamed joints of people with psoriatic arthritis.
- Genetics: With genetics as a decisive factor, about 40% of people with psoriatic arthritis have a close family member with the same condition. That means that if someone in your most immediate family is affected by the condition, you too are at a higher chance to do so at some point.
- Infections: Some experts assume certain infections like streptococcal infections contribute in the formation of psoriatic arthritis; however, this is not conclusively confirmed.
- Trauma: Some studies conclude that psoriatic arthritis is also more likely to occur after injuries such as bone or joint traumas. Yet, additional research is required to confirm these findings.
- Overweight: Finally, those who are overweight have been found to be at a higher risk of developing psoriatic arthritis. Specifically, research identified that a higher BMI (body mass index) is indicative of an increased risk for the disease. This finding even holds true for the general population, who are not affected by psoriasis. The underlying reason is that fat tissue (adipose tissue) overproduces inflammatory proteins in the body. As the level of inflammatory markers is continuously increasing, this may then render obese individuals more prone to react to psoriatic arthritis triggers.
What type of psoriatic arthritis do you have?
There are various different types of psoriatic arthritis. Your doctor will help you to identify your type of the condition.
- Asymmetrical: Psoriatic arthritis most often occurs in an asymmetrical pattern in that it affects different joints on both sides of the body for around 70% of affected people.
- Symmetrical: If the same joints on both sides of the body are affected, the pattern is considered symmetrical.
- Oligoarticular: Mild psoriatic arthritis means an individuals is affected in up to four affected joins, and can be referred to as oligoarticular.
- Polyarticular: Severe psoriatic arthritis – with four or more affected joints – is also known as polyarticular.
- Spondylitis: This describes the inflammation of the spinal column. Typical symptoms are stiffness of the neck, the lower back and the sacroiliac joints. As a result, moving these affected areas will be painful.
- Enthesitis: This type refers to an inflammation of entheses – the parts where tendons or ligaments insert into the bones. Most commonly, Enthesitis develops on the bottom of the feet, the Achilles' tendons, and the places where ligaments connect to the spine, ribs and pelvis. This type of arthritis is solely prevalent in psoriatic arthritis and does not occur in any other form such as rheumatoid arthritis or osteoarthritis.
- Dactylitis: Also known as "sausage digits," this type describes the painful swelling of an entire finger or toe. The swellings usually occur asymmetrically, meaning that different fingers/toes are affected on both hands/feet. This form is another arthritis manifestation, which can be exclusively found amongst people with psoriatic arthritis.
- Distal interphalangeal predominant (DIP): This form of the condition is quite rare and affects the small joints at the end of fingers and/or toes. Nails are also frequently affected.
- Arthritis mutilans: As the most severe form of psoriatic arthritis, this type occurs in only 5% of people with psoriatic arthritis. Arthritis mutilans leads to deterioration of the bones (osteolysis), which can again involve severe deformation and restricted mobility. Ultimately, joints may be destroyed causing a shortening of fingers (‘telescope fingers’).
How is psoriatic arthritis diagnosed?
If you suspect to have arthritis due to persistent stiffness, pain and swelling, you are advised to visit your GP as soon as possible. Early recognition and fast treatment are essential to manage this disease, as a delay of just six months can lead to permanent joint damage. Your GP will refer you to a rheumatologist (a specialist in joint conditions), who will be able to diagnose joint problems as well as psoriasis. He will try and rule out other forms of arthritis and several tests may have to be taken to ensure that a correct diagnosis is given. In doing so, X-rays of your joints are normally taken as well as blood tests to check for inflammation.
What treatments are there for psoriatic arthritis?
As there is no cure, the main aim of psoriatic arthritis treatments is to alleviate symptoms, slow down the progression and improve your overall quality of life. Ideally, you should opt for a medication which treats both the psoriatic arthritis in your joints and the psoriasis on the skin. Common treatments include:
- Non-steroidal anti-inflammatory drugs (NSAIDs): NSAIDs may be prescribed as your first treatment and are used to relieve pain and inflammation. They can be given in various forms (e.g. tablets, creams, injections) and include traditional NSAIDs such as ibuprofen or diclofenac and COX-2 inhibitors such as celecoxib.
- Disease-modifying antirheumatic drugs (DMARDs): DMARDs are taken orally to reduce symptoms and to help slow down the progression of the condition.
- Corticosteroids: Corticosteroids reduce pain and can be consumed orally or via injection. They can offer fast relief, but need to be considered carefully due to significant side effects for long-term consumption.
- Biologics: Biological therapies are used if you have not responded to at least two different types of DMARDs. Given by injection, they take effect by stopping the immune system from falsely attacking your joints. As biologics can entail various side effects from swelling of the injected area to liver problems or blood count, you’ll need to take regular blood or urine tests when opting for this type of therapy.
Related diseases associated with psoriatic arthritis
Psoriatic arthritis is related to a number of serious comorbidities. Apart from conditions common for people with psoriasis such as depression, diabetes or cardiovascular disease, research additionally identified issues such as inner ear damage and fibromyalgia (causing pain and fatigue). So by treating your psoriatic arthritis, you may not only have a positive impact on your joints, but also on your overall physical and mental wellbeing.
Psoriatic arthritis and fatigue
Up to 50% of people with psoriatic arthritis are struggling with moderate-to-severe fatigue, which is often rated as one of the most cumbersome symptoms of the condition. The causes of this debilitating fatigue are multifaceted; coexisting conditions such as fibromyalgia or depression can be one of them, as they arouse fatigue in many cases. Certain types of drugs used to treat psoriatic arthritis, particularly methotrexate, are also linked to fatigue. If you suspect medications to be responsible for your fatigue, you should talk to your doctor in order to work out the best treatment for you.
If you obtain the right treatment and are able to rule out fatigue-related comorbidities, making lifestyle changes can help. Regular exercise, a balanced diet (see below) and getting plenty of sleep may reduce inflammation and boost your energy levels.
Psoriatic arthritis and diet
The management of psoriatic arthritis and the related conditions is closely related to your diet. Here are some things to keep in mind when managing psoriatic arthritis:
- Eating a healthy diet: Make sure to eat a healthy, balanced diet with lots of fresh food like fruits and vegetables and reduce the intake of sugar, salt, fat and processed products. This will help to improve your overall health and wellbeing and to control weight. You could also consider taking supplements containing cod liver oil. The substance is known as a natural solution for inflammation and may therefore reduce the amount of anti-inflammatory drugs you need to take.
- Losing excess weight: If you are overweight, losing some pounds will help you to manage psoriatic arthritis better. As your joints are already dealing with psoriatic arthritis, you want to prevent any additional strain such as excess weight.
- Reducing alcohol: Limiting your intake of alcohol is another important factor, as alcohol might interfere with the effectiveness of your medication or could worsen side effects of some treatments.
- Stop smoking: According to studies, smokers with psoriatic arthritis report a higher number of painful body regions, a worse general health status and increased fatigue (in comparison to non-smoking people with psoriatic arthritis). Putting an end to smoking is always a good idea, so why not take this opportunity to do some good for your overall health and counteract psoriasis symptoms?
Psoriatic arthritis outlook
Psoriatic arthritis prognosis is positive, especially if there is an early diagnosis and if it is treated timely and correctly. While psoriatic arthritis can affect your quality of life, suitable therapy will reduce the symptoms associated with the condition and help you get the most out of life.
Psoriasis.org (2017). About psoriatic arthritis. Available from https://www.psoriasis.org/about-psoriatic-arthritis
Psoriasis.org (2017). About psoriasis. Available from https://www.psoriasis.org/about-psoriasis
Arthritis Foundation blog (2017). Obesity can increase the risk of psoriatic arthritis. Available from http://www.webmd.com/skin-problems-and-treatments/psoriasis/causes#1
Ross, E. (1997). Psoriatic arthritis and the immune system. Skin 'n' Bones Connection, 8, 3-4. Available from http://www.papaa.org/further-information/psoriatic-arthritis-and-immune-system
Papaa.org (2016). About psoriatic arthritis. Available from http://www.papaa.org/resources/about-psoriatic-arthritis#10
Thorarensen, S., Lu, N., Ogdie, A., Gelfand, J., Choi, H., & Love, T. (2016). Physical trauma recorded in primary care is associated with the onset of psoriatic arthritis among patients with psoriasis. Annals Of The Rheumatic Diseases, 76(3), 521-525. Available from http://ard.bmj.com/content/74/Suppl_2/190.3
Jon Love, T., Zhu, Y., Zhang, Y., Wall-Burns, L., Ogdie, A., Gelfand, J., & Choi, H. (2012). Obesity and the risk of psoriatic arthritis: a population-based study. Annals Of The Rheumatic Diseases, 71(8), 1273-1277. Available from http://ard.bmj.com/content/71/8/1273
Papaa.org (2017). A beginner's guide to psoriatic arthritis. Available from http://www.papaa.org/beginners-guide-psoriatic-arthritis
Roubille, C., Richer, V., Starnino, T., McCourt, C., McFarlane, A., & Fleming, P. et al. (2015). Evidence-based recommendations for the management of comorbidities in rheumatoid arthritis, psoriasis, and psoriatic arthritis: Expert opinion of the Canadian Dermatology-Rheumatology Comorbidity Initiative. The Journal Of Rheumatology, 42(10), 1767-1780. Available from http://www.jrheum.org/content/jrheum/42/10/1767.full.pdf
Eder, L., Chandran, V., Cook, R., & Gladman, D. (2017). The Risk of Developing Diabetes Mellitus in Patients with Psoriatic Arthritis: A Cohort Study. The Journal Of Rheumatology, 44(3), 286-291. Available from http://www.jrheum.org/content/44/3/286
Tobin, A.-M., Veale, D. J., Fitygerald, O., Rogers, S., Collins, P., O’Shea, D., & Kirby, B. (2010). Cardiovascular disease and risk factors in patients with psoriasis and psoriatic arthritis. The Journal of Rheumatology, 37(7), 1386-1394. Available from http://www.jrheum.org/content/jrheum/37/7/1386.full.pdf
Amor-Dorado, J., Barreira-Fernandez, M., Pina, T., Vazquez-Rodriguez, T., Llorca, J., & Gonzalez-Gay, M. (2014). Investigations into audiovestibular manifestations in patients with psoriatic arthritis. The Journal Of Rheumatology, 41(10), 2018-2026.Available from http://www.jrheum.org/content/41/10/2018
Psoriasis.org (2015). Fatigue and psoriatic arthritis. Available from https://www.psoriasis.org/advance/fatigue-and-psoriatic-arthritis
Nhs (2008). Cod liver oil reduces painkiller use. Available from http://www.nhs.uk/news/2008/03March/Pages/Codliveroilreducespainkilleruse.aspx
Arthritis.org. (2017). Psoriatic arthritis self care. Available from http://www.arthritis.org/about-arthritis/types/psoriatic-arthritis/self-care.php
Bremander, A., Jacobsson, L., Bergman, S., Haglund, E., Löfvendahl, S., & Petersson, I. (2014). Smoking is associated with a worse self-reported health status in patients with psoriatic arthritis: data from a Swedish population-based cohort. Clinical Rheumatology, 34(3), 579-583. Available from https://link.springer.com/article/10.1007/s10067-014-2742-8
Nhs.uk (2016). NSAIDs. Available from http://www.nhs.uk/Conditions/Anti-inflammatories-non-steroidal/Pages/Introduction.aspx
This content is not intended to advise you about your health. Always seek advice from your doctor or other qualified healthcare professionals.
UK/IE MAT-09232 Date of prep: May 2017