What is

Psoriatic Arthritis?

A positive approach

to psoriasis and

psoriatic arthritis

What are the aims of this leaflet?This leaflet has been written to help you understand psoriaticarthritis, the ways in which it is different from other forms ofarthritis, and the treatments available.

What is psoriasis?Psoriasis (sor-i’ah-sis) is a long-term (chronic) scaling diseaseof the skin, which affects about 2% of the UK population. Itusually appears as red, raised, scaly patches known asplaques. Any part of the skin surface may be involved but theplaques most commonly appear on the elbows, knees andscalp. It can be itchy but is not usuallypainful. Nail changes, includingpitting and ridging, are present in80% to 90% of people withpsoriatic arthritis (this falls to40% of those with psoriasisalone). Up to 30% of peoplewith psoriasis will developpsoriatic arthritis.There does not seem to be

any link between the severityof the psoriasis affecting theskin and the psoriatic arthritis.

What happens in psoriasis?Normally a skin cell matures in 21 to 28 days and during thistime it travels to the surface, where it is lost in a constantinvisible shedding of dead cells.In patches of psoriasis the turnover of skin cells is much

faster, around 4 to 7 days, and this means that even live cellscan reach the surface and accumulate with dead cells. Theextent of psoriasis and how it affects an individual varies fromperson to person. Some may be mildly affected with a tinypatch hidden away on an elbow which does not bother themwhile others may have large visible areas of skin involved thatsignificantly affect daily life and relationships. This process isthe same wherever it occurs on the body. Psoriasis is notcontagious. For more detailed information on psoriasis see ourleaflet What is Psoriasis? or visit our website.

What happens in psoriaticarthritis?Psoriatic arthritis (PsA) is a form of arthritis affecting individualswith psoriasis.

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� Joints become inflamed, which causes pain, swelling andstiffness.

� Tendons may also become inflamed and cause pain (oftenaround the heel or in the elbow).

� Joints are typically stiff after resting, particularly early in themorning or in the evening.

� Up to 30% of those with psoriasis may develop some formof arthritis.

� In most people (80%) the arthritis develops after theappearance of psoriasis.

� Some people may develop a condition of the eye (uveitis)which may cause redness and inflammation. If you areconcerned about this, seek medical advice.

� People with psoriatic arthritis often report feeling fatiguedor exhausted.

� There is some evidence that people with psoriasis and/orpsoriatic arthritis might have a slightly increasedcardiovascular risk (heart disease). See our Psoriasis andthe Heart leaflet.

How do joints and tendonsbecome inflamed?The funct ion of a jo int is to a l lowmovement to occur between bones.In the joint, the end of the bone iscovered with cartilage, aroundwhich is a capsule lined by amembrane called synovium.This membrane makes the

fluid that lubricates the jointspace, allowing movement. Inarthritis the synovial membranebecomes inflamed and releasess u b s t a n c e s t h a t c a u s einflammation.The inflamed synovium releases more fluid

than normal and so the joint becomes tender and swollen.Persistent inflammation may lead to damage to the cartilageand erosion of the underlying bone.The synovial membrane also lines and lubricates tendons,

so overproduction of synovial fluid can also cause tendoninflammation.

What is different about psoriaticarthritis?There are several features that distinguish psoriatic arthritisfrom other forms of arthritis.

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� The pattern of joints that may be involved is different.� Psoriatic arthritis may just affect a small number of joints

(oligoarthritis) or many joints (polyarthritis). Most commonlythe psoriatic arthritis is asymmetric in pattern (unlikerheumatoid arthritis, which is symmetrical).

� Psoriatic arthritis may affect the end joints of fingers, oftencorresponding with the fingers that have psoriatic nailinvolvement. See our Nail Psoriasis leaflet.

� When psoriatic arthritis affects the joints of the spine andsacroiliac joints it is called spondylitis (similar to ankylosingspondylitis). This can result in stiffness and pain of the backor neck.

� An entire toe or finger can become swollen or inflamed(dactylitis).

� Some people have involvement of the jaw or jointsaffecting the rib cage.

� Psoriatic arthritis may affect where the tendons connect tothe bone (enthesitis). Common areas to be affected includethe heel and ankle.

� Psoriatic arthritis may cause joints to become stiff and limittheir range of movement. In some severe cases the jointmay fuse, with the result that it cannot be moved.

� Importantly, the absence of rheumatoid factor in the bloodhelps distinguish psoriatic arthritis from rheumatoidarthritis.Distinguishing features are not always present and the

individual may have swelling of a few or many joints similar toother types of arthritis, making diagnosis difficult.

At what age and who doespsoriatic arthritis affect?� It may come on at any age.� It is uncommon in children.� Usually (in 80% to 90% of cases) the psoriatic arthritis

comes on after the psoriasis.� Men and women are equally affected.� 60% of men will develop arthritis of the spine as opposed

to 40% of women.

What is the outlook in psoriaticarthritis?� Although psoriatic arthritis cannot be cured at present,

many effective treatments exist.� Treatments will depend on the severity of the disease, with

some individuals having minimal arthritis while others aremore severely affected.

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� Psoriatic arthritis is a chronic condition that may wax andwane.

� Early diagnosis is essential in order to identify those whomay develop more severe psoriatic arthritis and begintreatment that can prevent damage occurring to the joints.If you or a first-degree relative have psoriasis and you havethe symptoms described in this leaflet (such as joint pain,stiffness, swelling or sausage finger), you should seekmedical advice.

� If you are concerned you may havepsoriatic arthritis something youcould do for yourself is tocomplete the PsoriasisEpidemiology ScreeningTool (PEST) questionnaire- the link is available inthis leaflet. A score of 3o r mo re ou t o f 5 i spositive and indicates areferral to rheumatologyshould be considered; yourGP will be able to help with this.

� Only a small minority of individualswill go on to develop severe and widespread joint damage.

� Joints that are initially involved in psoriatic arthritis areusually the ones that continue to cause the problems at alater stage, though this is not always the case.

� Genetic markers to identify individuals with potentiallymore severe arthritis are now becoming practical and willhelp in identifying the most suitable type of treatment.

What is the treatment for psoriaticarthritis?Although psoriatic arthritis is a chronic condition with no cure,there are many effective treatments to manage and control it.Some treatments for psoriatic arthritis may also help psoriasisof the skin. See our What is Psoriasis? leaflet for furtherinformation.Your psoriatic arthritis is likely to be managed by a number

of healthcare professionals, which may include:� your general practitioner (GP)� a rheumatologist (joint specialist)� a dermatologist (skin specialist)� a specialist nurse � a physiotherapist� an occupational therapist� a podiatrist (foot care)

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� an ophthalmologist (eye specialist)

� a surgeon (joint replacement).

You may also be referred forspecialist tests and imagery.These may include, whenappropriate, x-rays, magneticresonance imaging (MRI),ultrasound etc. Dependingo n y o u r i n d i v i d u a lcircumstances you may beoffered some of the followingdifferent types of treatments.� Topical analgesic creams for the

treatment of mild to moderate paincaused by arthritis.

� Topical medications for skin psoriasis such as vitamin Dderivatives, although they may help the skin, have not beenshown to benefit joints.

� NSAIDs (non-steroidal anti-inflammatory drugs) work byblocking the production of some of the body’s chemicalsthat cause inflammation and pain.

� csDMARDs (conventional synthetic disease-modifyinganti-rheumatic drugs) are often prescribed in addition toNSAIDs to help slow down the biological processes thatcause the persistent inflammation.

� Corticosteroids as joint injections can be very effective,although these do not work equally well in all individuals.They are safe when used in moderation and with precision.

Targeted synthetic drugs (such as the PDE4 inhibitors),biologics or bDMARDs (such as anti-TNF, interleukin inhibitors(IL 12/23, IL17) and small molecules (such as the janus kinase-or JAK inhibitors) have been developed in recent years andmay be offered if you do not respond effectively to otherDMARDs. They act by mimicking the effects of substancesmade naturally in the human immune system. Medical adviceis vital about medications that can control inflammation andjoint damage.A severely inflamed joint should be treated with a period of

rest followed by exercise (under medical supervision).Physiotherapy of joints and muscles which have stiffened canhelp prevent loss of movement. See our Physiotherapy &Exercise: Psoriatic Arthritis leaflet.

Remember: all treatments may have unwanted side effects orrequire special precautions (e.g. during pregnancy). Alwaysmake sure you have all the information before embarking onany course of therapy; this includes reading the patientinformation leaflets (PIL) provided with your medicines.

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Does diet make a difference?� No particular diet is uniformly effective; some people with

psoriatic arthritis have found cutting down on saturatedfats helps and may reduce the doses needed of othertreatments, though research has not confirmed this.

� Dietary supplements such as evening primrose oil andcertain fish oils may have a variable effect. They are safeand have other health benefits, but effects specificallybeneficial to psoriatic arthritis have not been proven inresearch.

� Following guidelines about healthy lifestyle, keeping weightdown and moderating alcohol intake are all generallyaccepted as beneficial regardless of having psoriasis orpsoriatic arthritis. Keeping weight in the healthy range (notbeing overweight or obese) has been shown to improve the likelihood of responding to medication. For moreinformation see our Psoriatic Lifestyle leaflet.

Remember: many so-called cures for arthritis are not provenby clinical trials to be of use and may be driven by profit tothose advocating them.

Does climate make a difference?� Ultraviolet light helps psoriasis in some cases, otherwise

climatic conditions such as the weather have a minor roleto play; those whose skin and joints wax and wanetogether are usually better in summer than winter.

Does the severity of skin or nailpsoriasis matter?� Nail changes are found in 80% of individuals with psoriatic

arthritis, compared with only 40% in those with psoriasisalone.

� Nail changes include pitting and discolouration of the naildue to abnormalities in the growth of tissue in the nailbed.

� The risk of developing psoriatic arthritis is greater inindividuals with severe psoriasis, yet severe psoriaticarthritis may occur with minimal skin disease.

Do we know what causespsoriatic arthritis?� The cause of psoriatic arthritis is the subject of much

research.

� You cannot catch psoriatic arthritis or psoriasis fromsomeone else. Therefore they are not contagious.

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� The cause of psoriatic arthritis is not proven but expertsbelieve it to be a combination of genetic, immunologicaland environmental factors. 40% of people with psoriasisor psoriatic arthritis have a first-degree relative with thecondition. This means you have a higher chance ofdeveloping psoriasis or psoriatic arthritis if you haverelative who has the condition. Some experts believeinfections such as streptococcal infections may provokepsoriatic arthritis, though this is not proven.

� The role of bacteria in the gut (the microbiome) anddeveloping psoriatic arthritis is the subject of currentresearch.

� Trauma and stress may be contributing factors, althoughthis is not proven.

� The genetic make-up of an individual is likely to determinethe risk of developing psoriasis and psoriatic arthritis andprobably influences the severity.

� Being overweight (obesity) is now understood to be linkedto developing psoriatic arthritis and is the subject ofongoing research.

� There are certain genetic markers linked to the immunesystem which are now being used to predict the severityof psoriatic arthritis. Much more is known about themechanisms that lead to inflammation in other conditionsand it is likely advances in science will lead to much moreeffective treatments with fewer side effects.

Where can I get more information?Around 90% of UK adults have access to the internet – whichis the easiest place to find more information. For those withoutinternet access or who cannot get online, the options arebecoming limited. A good place to start is the local publiclibrary, which often holds useful information. It may not be onimmediate display, however, so try asking at the main desk. Itis also worth asking your local GP surgery or hospital, whichshould have information in an accessible format.

Can I get financial support?Many people worry about what happens if they cannot workor need financial help because of the effects of psoriaticarthritis. Fortunately for many, with good therapy andmanagement the condition can be controlled and allow for afull and active working life. But if you do find that even for ashort period of time you are likely to need help, visit thenational government websites online. If it is easier, contactyour local government or council office, where you should bedirected to the appropriate resource and information.

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Useful contacts

For information about health matters in general and how toaccess services in the UK, the following websites providenational and local information.

� NHS Choices (England): www.nhs.uk

� NHS 24 (Scotland): www.nhs24.com

� Health in Wales: www.wales.nhs.uk

� HSCNI Services (Northern Ireland):http://online.hscni.net

These sites are the official sites for the National HealthService and provide links and signposting services torecognised organisations and charities.

References:Gelfand JM, Weinstein R, Porter SB, Neimann AL, Berlin JA,Margolis DJ. Prevalence and treatment of psoriasis in theUnited Kingdom: a population-based study. Arch Dermatol2005; 141:1537-41.

Cohen MR, Reda DJ, Clegg DO. Baseline relationshipsbetween psoriasis and psoriatic arthritis: analysis of 221patients with active psoriatic arthritis. Department of VeteransAffairs cooperative study group on seronegativespondyloarthropathies. J Rheumatol 1999; 26:1752-6.

Alamanos Y, Voulgari PV, Drosos AA. Incidence and prevalenceof psoriatic arthritis: a systematic review. J Rheumatol 2008; 35:1354-8. 10

Ibrahim G, Waxman R, Helliwell PS. The prevalence ofpsoriatic arthritis in people with psoriasis. Arthritis Rheum2009; 61:1373-8.

Krueger JG, Bowcock A. Psoriasis pathophysiology: currentconcepts of pathogenesis. Ann Rheum Dis 2005; 64Suppl2:ii30-6.

Gladman DD, Shuckett R, Russell ML, Thorne JC, SchachterRK. Psoriatic arthritis (PsA) - an analysis of 220 patients. Q JMed 1987; 62:127-41.

Gladman DD, Antoni C, Mease P, Clegg DO, Nash P. Psoriaticarthritis: Epidemiology, clinical features, course, and outcome.Ann Rheum Dis 2005; 64Suppl 2:ii14-7.

Stoll ML, Punaro M. Psoriatic juvenile idiopathic arthritis: a taleof two subgroups. Curr Opin Rheumatol

Alamino RP, Maldonado Cocco JA, Citera G, et al. Differentialfeatures between primary ankylosing spondylitis andspondylitis associated with psoriasis and inflammatory boweldisease. J Rheumatol

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McHugh NJ, Balachrishnan C, Jones SM. Progression ofperipheral joint disease in psoriatic arthritis: A 5-yr prospectivestudy. Rheumatology (Oxford) 2003;42:778-83.

Ritchlin CT, Kavanaugh A, Gladman DD, et al. Treatmentrecommendations for psoriatic arthritis. Ann Rheum Dis2009;68:1387-94.

Gelfand JM, Gladman DD, Mease PJ, et al. Epidemiology ofpsoriatic arthritis in the population of the United States. J AmAcadDermatol 2005; 53:573.

Mease P, Hall S, FitzGerald O, van der Heijde D, Merola JF,Avila-Zapata F, Cieślak D, Graham D, Wang C, Menon S,Hendrikx T, Kanik KS. Tofacitinib or Adalimumab versusPlacebo for Psoriatic Arthritis. N Engl J Med 2017 Oct 19; 377(16): 1537-1550

Coates LC, Kavanaugh A, Mease PJ, Soriano ER, LauraAcosta-Felquer M, Armstrong AW, Bautista-Molano W,Boehncke WH, Campbell W, Cauli A, Espinoza LR, FitzGeraldO, Gladman DD, Gottlieb A, Helliwell PS, Husni ME, Love TJ,Lubrano E, McHugh N, Nash P, Ogdie A, Orbai AM, ParkinsonA, O’Sullivan D, Rosen CF, Schwartzman S, Siegel EL, TolozaS, Tuong W, Ritchlin CT. Group for Research and Assessmentof Psoriasis and Psoriatic Arthritis 2015 TreatmentRecommendations for Psoriatic Arthritis. Arthritis Rheumatol.Epub 2016 Mar 23. 2016 May; 68(5): 1060-71. doi:10.1002/art.39573.

J Eur Acad Dermatol Venereol. Obesity and psoriasis: bodyweight and body mass index influence the response tobiological treatment. Epub 2011 Apr 15. 2011 Sep; 25(9):1007-11. doi: 10.1111/j.1468-3083.2011.04065.x.

Yan D, Issa N, Afifi L, Jeon C, Chang HW, Liao W. The Role ofthe Skin and Gut Microbiome in Psoriatic Disease. Epub 2017Apr 22. Curr Dermatol Rep. 2017 Jun; 6(2): 94-103. doi:10.1007/s13671-017-0178-5.

Juan D Cañete, Philip Mease The link between obesity andpsoriatic arthritis http://dx.doi.org/10.1136/annrheumdis-2012-201632

http://www.nhs.uk/Change4Life [accessed February 2016] NEngl J Med 2009;361:496-509

Office for National Statistics – Adult internet usage2015http://www.ons.gov.uk/ons/dcp171778_404497.pdf [accessedFebruary 2016]

http://www.bad.org.uk/shared/get-file.ashx?id=1655&itemtype=document [accessed February 2018]

Further references used in the production of PAPAA informationcan be found at: www.papaa.org/resources/references

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About this informationThis material was produced by PAPAA. Please be aware thatresearch and development of treatments is ongoing.For the latest information or any amendments to this material

please contact us or visit our website www.papaa.org. The sitecontains information on treatments and includes patientexperiences and case histories.Original text written by Professor Neil McHugh, consultant

rheumatologist, Royal National Hospital for RheumaticDiseases, Bath, UK, in August 1996.Reviewed/revised September 1997, May 1998, March 2002,

July 2004, July 2007, November 2007, March 2010 and July 2011.This edition reviewed and revised by Dr William Tillett,

consultant rheumatologist and Lead for Biological Therapies,Royal National Hospital for Rheumatic Diseases, Bath, UK,October 2013, February 2016 and February 2018.

A lay and peer review panel has provided key feedback on thisleaflet. The panel includes people with or affected by psoriasisand/or psoriatic arthritis.

Published: March 2018

Review date: March 2020

© PAPAA

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The charity for peoplewith psoriasis and psoriatic arthritis

PAPAA, the single identity of the Psoriatic Arthropathy Alliance and the

Psoriasis Support Trust.

The organisation is independently funded and is aprincipal source of information and educationalmaterial for people with psoriasis and psoriatic

arthritis in the UK.

PAPAA supports both patients and professionals byproviding material that can be trusted (evidence-

based), which has been approved and contains nobias or agendas.

PAPAA provides positive advice that enablespeople to be involved, as they move through their healthcare journey, in an informed way which is appropriate for their needs and any

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WPSA/03/18

ISBN 978-1-906143-07-7