What is psoriatic arthritis?

Psoriatic arthritis is an inflammatory disease which occurs when the body’s immune system begins to attack healthy cells and tissue.3

The disease will most often develop in people who already experience psoriasis, although the arthritis can occur first. In certain cases, both diseases can be diagnosed at the same time and it has been known for both to first appear concurrently.4

It is not yet known what causes psoriatic arthritis, but it is thought that some people’s genes make them more likely to develop it than others. Research suggests that a trigger might cause the disease to start, especially in people who are already at risk.5

No trigger has yet been found, but it is suspected that an infection or a variety of infections (for example bacteria that live in patches of psoriasis) might be involved.6

Over time, there will be periods when the symptoms a person experiences become worse, known as a ‘flare’, and improve, known as ‘remission’.3 Psoriatic arthritis cannot be transmitted by having contact with someone who has the condition.7,8

Psoriatic arthritis is considered a ‘chronic’ disease, which means it can persist for a long time or constantly reoccurs.7,9

What is the impact of psoriatic arthritis?

Psoriatic arthritis is a diverse condition, affecting each person differently.1 Experts have identified six different ‘manifestations’ (called ‘domains’ by healthcare professionals) that people may experience.10 These are:


Peripheral arthritis

Swelling, pain and/or stiffness in joints that are not in the spine or buttocks, for example in the hands, feet, and/or knees.11



Swelling, pain and/or stiffness where tendons connect to the bone.12



The swelling of a whole finger and/or toe.13,14,15


Axial disease

Pain and/or stiffness in the joints of the spine and/or buttock region11



A condition which causes dry, red, crusty skin patches and chronic itch.16


Nail disease

Dents, discolouration and/or abnormal nail growth.17

Not everyone will experience all six, but each person will have his or her own combination of manifestations,1 which will vary in severity and the impact on day-to-day life.9 So far, our questionnaire results have shown up to 57 various combinations of domains, with 1 in 5 people experiencing all six.


The six domains of psoriatic arthritis


Peripheral arthritis

Peripheral arthritis causes pain, swelling, tenderness or morning stiffness in joints of the body that are not in the spine or buttocks.11 Of those completing the What’s Your Combination questionnaire, 87.8% reported experiencing peripheral arthritis, making it the most common domain. Be sure to understand how this domain can affect a person with psoriatic arthritis.

What to look for:

Due to peripheral arthritis, the joints in  hands, feet, wrists, knees and/or ankles can sometimes be swollen and feel painful, stiff or hot to the touch.11



Enthesitis can present as swelling, pain and stiffness at the point where tendons connect to a bone.12

It can be felt:

  • In the back of the heel
  • In the bottom of the heel/foot (called plantar fasciitis or policeman’s heel)
  • Around or to the side of the elbow
  • On the side of the hip (which causes a person pain when lying on their side)
  • Around the front of the knee

The difference between enthesitis from general arthritic pains is that the pain is often either felt next to a joint or spread out over a wider area. The symptoms of enthesitis are not constant; they can appear and then go away.18 From our questionnaire, over 50% of respondents who experienced enthesitis were unaware it was linked to psoriatic arthritis.*



Dactylitis causes an entire finger or toe to become swollen, which can be painful and limit how much it can be moved.3,13,14,15

What to look for:

The swelling gives fingers or toes a sausage-like appearance, which has led to dactylitis sometimes being called ‘sausage fingers or toes.13,14,15


Axial disease

Axial disease may cause pain and stiffness in the back and buttocks, due to involvement of spine and sacroiliac joints (joints that connect the spine to the pelvis).11

What to look for:

With axial disease the back or buttocks can sometimes feel painful or stiff.11  This tends to be worst in the morning hours or after periods of rest.15 In selected cases, axial disease may also reduce spine movement.11



Psoriasis can present as skin plaques and be associated with ‘lesions’ on the skin and chronic itching.19 These will most often appear on the elbow, knee, scalp, genital areas and lower back regions, but can be found anywhere on the body19

What to look for:

  • Dry, red, crusty patches of skin, which might be covered in silver scales16,20
  • These patches can be itchy, sore or both, and in some cases may crack and bleed16,20

Nail disease

Nail disease can affect both the fingers and toes, causing changes in the nail appearance.17

What to look for:

The most common changes seen are:

  • Tiny dents or pits, which can make the nail look like the surface of a thimble17
  • The nail becoming detached from the bed, with a gap developing under the nail17
  • The nail turning an unusual colour, such as a yellow-brown17
  • Abnormal growth on the nail17

*Interested in knowing the full set of results for all domains?
Read more about it by visiting the Questionnaire Results page.

Listen to other people's experience of living with psoriatic arthritis

Treating psoriatic arthritis

Although not curable, it is possible to manage and control psoriatic arthritis,9 and a number of different treatment options are available to help relieve symptoms and improve quality of life. With psoriatic arthritis affecting people in many different ways, treatment goals can vary greatly from person to person and finding the right treatment may involve trying a number of different medications.9

Because of this, it is important to work with your healthcare professional, for example a doctor or nurse, to find a treatment that is right for you.

Treatments that act on the domains of psoriatic arthritis may include:14


To help your rheumatologist find a treatment approach which is right for you, it is important to understand which of the six domains of psoriatic arthritis you experience and determine your personal treatment goals.


Psoriatic arthritis with other conditions

A person with psoriatic arthritis has a higher chance of developing some other chronic and serious health conditions, known as ‘comorbidities’. This can have a further impact on their disease burden. If you believe you experience any of these conditions, speak to your doctor.

The comorbidities of psoriatic arthritis include:21,22,23,24

  • Being overweight or obese
  • Diabetes
  • High blood pressure
  • High cholesterol
  • A build-up of fat in the liver, called fatty liver disease
  • Depression or anxiety
  • Chronic inflammation in the gut called Inflammatory Bowel Disease
  • Inflammation of specific parts of the eye, called uveitis
Find out about your individual disease


1. Kavanaugh A, et al. Rheumatol Ther 2016;3:91–102.
2. Aletaha D, et al. The many faces of psoriatic arthritis – a challenge to treatment to target? Reumatologia. 2016; 54(1): 1–2.
3. Mayo Clinic, Psoriatic Arthritis, Available at: https://www.mayoclinic.org/diseases-conditions/psoriatic-arthritis/symptoms-causes/syc-20354076. Accessed August 2018
4. Al Hammadi, et al., Psoriatic Arthritis – Overview, MedScape. Available at: https://emedicine.medscape.com/article/2196539-overview#a1. Accessed August 2018
5. Arthritis Research UK, What causes psoriatic arthritis?, Available at: https://www.arthritisresearchuk.org/arthritis-information/conditions/psoriatic-arthritis/causes.aspx, Accessed September 2018
6. Al Hammadi, et al., Psoriatic Arthritis – Pathophysiology and Etiology, MedScape. Available at: https://emedicine.medscape.com/article/2196539-overview#a4. Accessed August 2018
7. International Federation of Psoriasis Associations, World Psoriasis Day 2013, available at: https://ifpa-pso.com/wp-content/uploads/2017/01/WPD-2013-General-Summary.pdf. Accessed August 2018.
8. PAPAA, About Psoriatic Arthritis, Available at: http://www.papaa.org/resources/about-psoriatic-arthritis
9. NHS Choices, Psoriatic Arthritis, Available at: https://www.nhs.uk/conditions/psoriatic-arthritis/. Accessed July 2018
10. Coates LC, et al. Arthritis Rheumatol 2016;68:1060–71
11. Arthritis Foundation. Psoriatic Arthritis and Back Pain, Available at: https://www.arthritis.org/about-arthritis/types/psoriatic-arthritis/articles/psa-back-pain.php. Accessed September 2018
12. McGonagle, D. & Benjamin, M., Enthesis, enthesitis and enthesopathy, Arthritis Research UK, Available at: https://www.arthritisresearchuk.org/health-professionals-and-students/reports/topical-reviews/topical-reviews-autumn-2009.aspx. Accessed July 2018

13. National Psoriasis Foundation. About Psoriatic Arthritis. Available at: https://www.psoriasis.org/about-psoriatic-arthritis. Accessed September 2018
14. PAPAA. What is Psoriatic Arthritis, Available at: http://www.papaa.org/sites/default/files/WhatisPsa%20final_2018.pdf. Accessed July 2018
15. Psoriatic-arthritis.com. What Are Common Symptoms of PsA? Available at: https://psoriatic-arthritis.com/psa-symptoms/. Accessed September 2018
16. NHS. Psoriasis Symptoms. Available at: https://www.nhs.uk/conditions/psoriasis/symptoms/. Accessed September 2018
17. PAPAA, Nail Psoriasis, Available at: http://www.papaa.org/further-information/nail-psoriasis. Accessed July 2018
18. Enthesitis. Enthesitis Symptoms and Treatments. Available at: http://enthesitis.org/enthesitis-symptoms-treatments/. Accessed July 2018
19. National Institute of Arthritis and Musculoskeletal and Skin Diseases, Psoriasis, Available at: https://www.niams.nih.gov/health-topics/psoriasis. Accessed July 2018
20. Mayo Clinic, Psoriasis, Available at: https://www.mayoclinic.org/diseases-conditions/psoriasis/symptoms-causes/syc-20355840. Accessed September 2018.

21. Husted JA, et al. Arthritis Care Res (Hoboken) 2011;63:1729–35.
22. Edson-Heredia E, et al. J Eur Acad Dermatol Venereol 2015;29:955–63.
23. Ogdie A, et al. J Rheumatol 2014;41:2315–22
24 Ogdie A, et al. J Invest Dermatol 2017 [Epub].
25. Mayo Clinic, Caregiver stress: Tips for taking care of yourself, Available at: https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/caregiver-stress/art-20044784. Accessed August 2018.
26. Lebwohl MD, et al. J Am Acad Derm 2014;70:871–81.
27. Arthritis UK (2013). Caring for a person with arthritis. Published April 2013 2005/CARER/13-1
28. Carers UK (2018). Looking after someone (2018). Available at: www.carersuk.org Accessed August 2018.
29. Armstrong, A., Quality of Life and Work Productivity Impairment among Psoriasis Patients: Findings from the National Psoriasis Foundation Survey Data 2003–2011, PLOS ONE, 7(12)
30. Thompson A et al (2013). Building confidence in social situations: A guide for people living with a skin condition, including scars. http://skinsupport.org.uk/sites/default/files/Social%20Confidence%20Self-help%20Leaflet_0.pdf. Accessed August 2018.
31. PAPPA. Psychological Aspects Of Psoriasis. (2012). Available at:
www.papaa.org Accessed August 2018.


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Six Domains Programme was developed by Celgene

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