A positive approach

to psoriasis and

psoriatic arthritis

Nail Psoriasis

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What are the aims of this leaflet?This leaflet has been written to help you understandwhat nail psoriasis is, what changes can occur in thenails, what can be done and provide you with somegeneral tips on nail care.

What is psoriasis?Psoriasis (sor-i’ah-sis) is a long-term (chronic)scaling disease of the skin, which affects 2%-3% ofthe UK population. It usually appears as red, raised,scaly patches known as plaques. Any part of the skinsurface may be involved but the plaques mostcommonly appear on theelbows, knees and scalp. Itcan be itchy but is notusually painful. Nailchanges, includingpitting and ridging, arepresent in 40% to50% of people withpsoriasis alone. Around30% o f p eop l e w i t hpso r i as i s w i l l deve loppsoriatic arthritis. There does notseem to be any link between the severity of thepsoriasis affecting the skin and the severity ofpsoriatic arthritis. For more detailed information onpsoriasis see our leaflets What is Psoriasis? andWhat is Psoriatic Arthritis?

What happens in psoriasis?Normally a skin cell matures in 21-28 days andduring this time it travels to the surface, where it islost in a constant, invisible shedding of dead cells. Inpatches with psoriasis the turnover of skin cells is

much faster, around 4-7 days, and this means thateven live cells can reach the surface and accumulatewith dead cells. This process is the same whereverit occurs on the body. The extent of psoriasis andhow it affects an individual varies from person toperson. Some may be mildly affected with a tinypatch hidden away, while others may have large,visible areas of skin involved that can significantlyaffect daily life and relationships. Psoriasis is notcontagious, therefore you cannot catch it or pass itto another person. The cause of psoriasis is currentlyunknown.

What is nail psoriasis?

Psoriasis can affect both fingernails and toenails.The percentage of those with psoriasis who have nailinvolvement is thought to be up to 50%. In psoriaticarthritis this may rise to 80%. For some unknownreason fingernails are more often involved thantoenails. For many people, nail psoriasis is often mildand causes few problems. The nails are part of the

skin, so it is perhaps notsurprising that a skind i sease such aspsoriasis can affectthe na i ls . No oneknows why somep e o p l e g e t n a i linvolvement and othersdon’t. Nails grow from thenail root (matrix), which is justunder the cuticle. In people who develop nailpsoriasis it is involvement of the nail root that causespitting and ridging of the nails.Onycho lys i s , ( on- i k -o l - i s - i s ) subungua l

hyperkeratosis (sub-ung-gwal hi-per-ker-at-o-sis)and splinter haemorrhages (hem-or-ij-iz) are all

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caused by disease of the nail bed. These conditionsare explained in the next section.The nail is made of modified skin and, once it has

grown, it can only be altered by filing or clipping.Treatments are usually directed at the nail bed thatsupports the nail or the nail folds that tuck aroundthe edges. Soothing these tissues can result in betternail growth with fewer features of psoriasis.The severity of nail involvement does not follow the

severity of psoriasis elsewhere in the body, althoughlocally it can correspond to problems in the nearbyjoint of a finger or toe. On rare occasions, the nailscan be the only site of the body affected. Moreusually, if the nails are involved there will be areas ofpsoriasis elsewhere on the body. You can, however,develop severe nail changes with only minimalpsoriasis.

What changes can occur?These are the most common changes in nailpsoriasis:

� Pitting of the nails – the surface of the naildevelops small pits, looking rather like the surfaceof a thimble. The number of pits can vary fromone to dozens.

� Onycholysis – the nail becomes detached fromthe underlying nail bed and a gap develops underthe nail. When it starts there is a white or yellowishpatch at the tip of the nail, and this then extendsdown to the cuticle. The gap between the nail andthe nail bed can become colonised by particularbacteria, such as pseudomonas, which can thenproduce a dark green pigment. The nail canbecome infected and discoloured and can easilybe mistaken for melanoma under the nail.

� Subungual hyperkeratosis – a chalky substanceaccumulates under the nail. The nail becomes

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raised and can become tender, especially whenthe surface of the nail is pressed. Subungualhyperkeratosis of the toenails can be particularlyuncomfortable because when wearing shoes the nail may be put under constantpressure.

� D isco loura t ion – t h i s may be seenas unusual nail colouration, such as yellow-brown.

� Onychomycosis (on-ik-o-mi-ko-sis) – a fungalinfection that can cause thickening of the nails.This could be present alongside nail psoriasis andc a n b e c o n f u s e d i ndiagnosis. If diagnosedc o r r e c t l y i t c a n be t rea ted w i t hsystemic antifungalmedicat ion. I t ise s t i m a t e d t h a tapproximately 35%of people who havenail psoriasis may alsohave a fungal infectionthat could make the nails worse.Treating the fungal infection may not have anyeffect on the clearance of nail psoriasis.

Some nail changes are caused by using systemicretinoid medication, which can help the skin but mayresul t in format ion of very th in na i ls which do not appear normal. These nail changes can takeseveral months to grow out only after retinoids are stopped.

In addition to these changes you may getlongitudinal ridging of the nails and reddish marksunder the nails, called splinter haemorrhages, due totiny burst blood vessels under the nails.

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What can be done about it?Nail psoriasis is perhaps the most difficult part ofpsoriasis to treat. In the past a large number oftreatments have been tried, none of which has givenparticularly good results. The first things to considerare the non-medical aspects of caring for your nails.

Tips on general nail care

� The basic strategy for both hands and feet shouldbe to keep the nails short. Try to trim them backto the point of firm attachment and gently filethem down with an emery board.

� Try to protect your nails from damage becausethis can worsen the problem. Consider wearinggloves to protect your nails whenever you aredoing something that could cause damage.

� Do not clean debris from beneath the nail with asharp object or a nail brush. This tends toincrease any onycholysis and make the situationworse; soaking the affected nails in soapy warmwater may be sufficient to remove the debris.

� Rubbing moisturisers into the nail and cuticle orsoaking them in emollient oils may help.

� Toenails can benefit by being soaked for at least10 minutes in a bowl or bath of warm water, whichsoftens the nails, before gently filing the thickenedpart of the toenails with an emery board and usinggood, sharp scissors to trim off small pieces ofthe nails. You should cut straight across thetoenail, which helps prevent it from becomingingrown. It helps to always wear comfortableshoes which make enough room for your toes;friction can cause toenail thickening to occur. Itmay be worth considering buying shoes a size upfrom your normal size.

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Medical treatments include:

The use of topical steroids rubbed into the cuticle

– the nail plate is under the cuticle and by massagingsteroid creams into the nail plate you can inducesome improvement in nail psoriasis. Results are notconsistent however and there is the risk that thecuticle can become thinned with fine blood vesselsover the surface.

Anecdotally, a number of dermatologists noticedthat psoriasis of the nails improved when patientswere using vitamin D analogue preparations forpsoriasis of their skin. This led to a more focusedstudy of vitamin D analogue creams and ointmentsrubbed into the cuticle in the treatment of nailpsoriasis. Experience from around the world hasshown tha t t h i s i s ane f f ec t i ve me thod o ftreatment and shouldbe regarded as thefirst-line treatment ofchoice. The vitamin Danalogue cream orointment should bemassaged in to thecut ic le for about f iveminutes twice a day. Whenonycholysis is present, calcipotriol scalp solution canbe dripped under the nail and massaged in, which iseffective.

Remember t ha t na i l s g row ex t reme l y slowly and what you are influencing is not theexisting nail but new nail that is developing from thenail plate. It may, therefore, take up to a year forfingernails, and two years for toenails, to grow out normally; you will need to be patient with any treatment. It’s worth noting that toenails canfa i l to respond where f ingerna i ls improvesubstantially.

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Injections of steroids under the nail – theseusual ly require addit ional in ject ion of localanaes the t i c and a re no t a good rou t i ne treatment.

Removal of the nail – nails can be removed quitep a i n l e s s l y u s i n g a h i g hconcentration of ureaapplied under polytheneocclusion to the nail.The nail becomesrather jelly-like andcan be peeled off. Nails can be removedby surgery, however,nails may still often growback with an abnormalappearance. X-ray treatmentmay cause nail shredding, but is not an advisabletreatment in most instances.

Systemic treatments – where nail psoriasis issevere and you are not able to walk or use your handproperly, it may be possible to take tablet-based orother injected systemic treatment to improvepsoriasis on the nails and skin together.

Is there anything else I can do?If your fingernails are affected, that hand can bepainful and you may find the dexterity of your fingersis restricted. If the toenails are affected it’ssometimes helpful to seek attention from achiropodist, who may be able to remove the excessthickening of the nails to reduce the pressure whenwearing shoes. This can reduce pain and improvemobility. Specialist shoes may also prove helpful;you can easily find various suppliers by searching onthe internet or asking a chiropodist or podiatrist forrecommendations.

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Nail psoriasis can also be a cosmetic problem. Thenails may be distorted, which some people findembarrassing. Nail varnish can be used to concealsome of the damage. Application of a good nailhardener or wearing artificial nails if the nails aremostly intact can improve their appearance and alsohelp to protect them. Some people are sensitive tothe chemicals in the glue used to apply artificial nails,so it’s advisable to tell your manicurist about yourpsoriasis so that he/she can be extra careful. Also,where there is onycholysis, all nails should be keptshort and this includes gel nails. If nails are extendedby gel application or other form of artificial nail thenit is likely to make the nail bed psoriasis worse andincrease the onycholysis.If you have any views or comments about this

information or any of the material PAPAA producesyou can contact us via the details on the back pageor on line at www.papaa.org/user-feedback

Useful contactsFor information about health matters in general andhow to access services in the UK, the followingwebsites provide national and local information.

n NHS Choices (England): www.nhs.uk

n NHS 24 (Scotland): www.nhs24.com

n Health in Wales: www.wales.nhs.uk

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

These sites are the official sites for the NationalHealth Service and provide links and signpostingservices to recognised organisations and charities.

References

Gelfand JM, Weinstein R, Porter SB, Neimann AL,Berlin JA, Margolis DJ. Prevalence and treatment ofpsoriasis in the United Kingdom: A population-basedstudy. Arch Dermatol 2005;141:1537-41.

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Cohen MR, Reda DJ, Clegg DO. Baselinerelationships between psoriasis and psoriaticarthritis: Analysis of 221 patients with active psoriaticarthritis. Department of Veterans Affairs Cooperative Study Group on seronegativespondyloarthropathies. J Rheumatol 1999;26:1752-6.

Alamanos Y, Voulgari PV, Drosos AA. Incidence andprevalence of psoriatic arthritis: A systematic review.J Rheumatol 2008;35:1354-8.

Ibrahim G, Waxman R, Helliwell PS. The prevalenceof psoriatic arthritis in people with psoriasis. ArthritisRheum 2009;61:1373-8.

Krueger JG, Bowcock A. Psoriasis pathophysiology:Current concepts of pathogenesis. Ann Rheum Dis2005;64 Suppl 2:ii30-6.

The above list is not exhaustive. For furtherreferences used in the production of this andother PAPAA information contact us or go to:www.papaa.org/resources/references

About this informationThis material was produced by PAPAA. Please beaware that research and development of treatmentsis ongoing.

For the latest information or any amendments to thismaterial please contact us or visit our website:www.papaa.org. The site contains information ontreatments and includes patient experiences andcase histories.

Original text written by PAPAA in 2004. Peerreviewed by Dr David de Berker, ConsultantDermatologist and Honorary Clinical Senior Lecturer,

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The Information Standard scheme was developed by theDepartment of Health to help the public identify trustworthyhealth and social care information easily. At the heart of thescheme is the standard itself – a set of criteria that definesgood quality health or social care information and the methodsneeded to produce it. To achieve the standard, organisationshave to show that their processes and systems produceinformation that is:

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The assessment of information producers is provided byindependent certification bodies accredited by The UnitedKingdom Accreditation Service (UKAS). Organisations thatmeet The Standard can place thequality mark on their informationmaterials and their website - areliable symbol of quality andassurance.

Bristol Dermatology Centre, Bristol Royal Infirmary,Bristol, in June 2013, August 2015 and in April 2018.

A lay and peer review panel has provided keyfeedback on this leaflet. The panel includes peoplewith or affected by psoriasis and/or psoriaticarthritis.

Published: June 2018

Review date: October 2020

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