Focus on CME at Dalhousie University

The Canadian Journal of CME / November 2003 105

It is estimated that about 26,000 new cases ofpsoriasis arise in Canada every year, with the

average age of onset being 31.In Canada, psoriasis affects about 700,000

people (about 2% of the population). The condi-tion creates a major psychosocial impact on theaffected patient. The age group most affected is18 to 54. Difficulties in workplace interactionaffect 18% of all patients. Fifteen per cent ofpatients show difficulties concerning socializingwith family and friends, while 8% of patientshave been excluded from using public facilities,such as swimming pools or spas. Five per cent ofpatients indicate difficulty in getting a job and,most troublesome of all, 10% of patients havecontemplated suicide.

A review of 40,000 patients was carried out inthe March 2001 issue of The Archives ofDermatology (Table 1). Patients indicated thatphysicians underestimate the seriousness orrepercussions of psoriasis. Depression, frustra-tion, and embarrassment are pervasive in thesepatients. There is a different patient perceptioncompared with physician perception of the seri-ousness of the problem. Patient frustration levelsare high and alternative therapies are common.

Activities of daily life are affected signifi-cantly. Twenty per cent of patients have experi-enced sleeping difficulties, while 27% suffer

sexual difficulties. Hand use has been difficultin 8% of patients, and 7% of patients have diffi-culty walking. Sitting for prolonged periods oftime is a problem in 7% of patients (e.g., sittingat a computer), and standing for long periodswas a complaint in 5% of those surveyed. In gen-eral, job duties were difficult to perform in atleast 10% of patients.

A. H. Murray, MD, FRCP(C)

Presented at the 76th Annual Dalhousie Refresher Course

Andrea’s eruption

Andrea, 26, presents with afour-week history of awidespread cutaneous eruption.She has never had this problembefore. Two weeks prior to theskin problem, Andrea developedan upper respiratory infection,which as since disappeared.

Andrea, whose only medicationis the birth control pill, has a sister with psoriasis.

On physical examination, there is a widespreadmacular and papular cutaneous eruption on her trunkand extremities. Her scalp is involved, but the palms,soles, and mucous membranes are spared. There arenumerous 0.5 cm to 1 cm-sized papules and patchescovering the skin. Each lesion has a silvery scale.There are no changes seen in the nails.

What is the diagnosis? See page 107

Set On Soothing

Psoriasis

106 The Canadian Journal of CME / November 2003

The take-home message concerning these sta-tistics is clearly that we can do better.

What causes psoriasis?First of all, there are different types of psoriasis,including plaque, guttate, pustular, and erythro-dermic.

The actual cause of psoriasis is unknown.Genetics determine the predisposition of the typeof psoriasis that will develop and environmental

factors may trigger the condition itself. There is animmune reaction taking place and this is now thefocus of the newer therapies.

It seems that the epidermal keratinocyte turnsover about seven times the normal rate in patientswith psoriasis. New research suggests that it is amessage from the T lymphocyte that is a majorcontributor to the development of psoriasis.Newer therapies focus on this.

What are the treatments?In the histology of psoriasis, there is a hyperpro-liferation and abnormal differentiation of ker-atinocytes. There is inflammation and a local vas-cular change.

Currently, topical agents are the mainstay oftherapy, and this is reflected in the fact that 87% ofpatients are using topical creams or ointments(Table 2). Topical corticosteroids are still a first-line agent. It is important to have an approach thatincludes the knowledge of various potencies oftopical corticosteroids. Generally speaking, welike to use medium-strength to low-strength topi-cal corticosteroids because the use of long-termhigh potency steroids comes with many potentialside-effects. Creams are preferred over ointmentsbecause they are cosmetically more acceptable.Lotions will be used on the scalp, and pastes canbe used in areas where psoriasis is quite thick.

Topical vitamin D derivatives have been usedover the past 10 years. Calcipotriol has beenproven very effective. It is often used in combina-tion with a topical steroid and is currently avail-able in a combination called Dovobet®. It can beextremely beneficial when used in conjunctionwith ultraviolet (UV) light therapy.

Tazarotene is a vitamin A topical retinoid. It isavailable as gel or cream, and has been useful insome patients with psoriasis. It can be used in

Psoriasis

Dr. Murray is an associate professor, department of dermatology, faculty of medicine,Dalhousie University, Halifax, Nova Scotia.

Table 1

National Psoriasis Foundation survey

Part of a recent survey by the National PsoriasisFoundation involved how satisfied participants werewith therapy. Patients’ responses were:

Very 26%

Fairly 22%

Somewhat 36%

Not at all 36%

Not sure 3%

Patients were also asked to estimate the efficacy ofcurrent therapy, and this is summarized as follows:

Very well 22%

Fairly well 32%

Somewhat 36%

Not at all 10%

short contact or may be left on for a more pro-longed period.

Anthralin has been available for over 80 years.Anthralin can be used either as a short contact, oron a more prolonged basis. The problem with thisproduct is that it stains the skin and, for that rea-son, some patients find it less cosmeticallyacceptable.

Tars have been used alone, as well as in combi-nation with light therapy, for a long time. Their usehas become more limited since newer agents havebeen made available. Tars do still play an impor-tant role to play in resistant cases of psoriasis.

The addition of products, such as salicylic acid,to creams or ointments, canalso be beneficial.

Combination therapy ofcalcipotriol and steroids,tazarotene and steroids,anthralin and tar, and sali-cylic acid and steroids issomething that one canimplement when othermeans fail.

Phototherapy has beenused to treat psoriasis for along time. UVB light, UVAlight combined with pso-ralens (PUVA), and narrowband UV light therapy are

available in most major centres. These treatmentsare reserved for patients with very extensive pso-riasis, and they come with a side-effect profilethat must be reviewed with the patient carefully.Patients receiving UV light therapy must be madeaware that there is a higher incidence of skin can-cer (basal cell carcinoma, squamous cell carcino-

Table 2

Current use of prescription products

Therapy % of all patients

Topicals 87%(creams, ointments, and lotions)

Phototherapy or 21% light treatment

Oral medications 18%

Psoriasis

Andrea’s diagnosisAndrea has guttate psoriasis. The differentialdiagnosis includes:

• Pityriasis rosea • Secondary Syphilis• Lichen Planus

The distribution and morphology rule out the latterthree entities. The serology is negative and the onlylab data which is positive is an elevated ASOT.

The management of guttate psoriasis includes theuse of a mild topical corticosteroid cream, such as1% hydrocortisone, and ultraviolet B light therapy, ifit is available.

Andrea responded to the above treatment within twoand a half weeks, and was virtually clear at that time.

Indicated for the maintenance treatment of asthma in patients where the use of a combination product isappropriate. See Product Monograph for patient selection, warnings, precautions and adverse events.

Mississauga, Ontario L5N 6L4

ma, and even melanoma) when these treatmentsare used.

PUVA therapy can be given with the use ofpills, or as a bath. Use of PUVA requires constantsupervision, and the watchful eye of a trained indi-vidual in order to achieve the desired effects.

Oral medications, such as methotrexate,retinoids, and cyclosporine are available topatients.

The medication which has been around thelongest is methotrexate.It is reserved for patientswith very extensive pso-riasis who fail to respondto topical therapy.Because methotrexate ismetabolized in the liver,it is very important thatpatient monitoring beperformed very careful-ly. If there is a history of excessive alcohol inges-tion, the patient would not be a candidate. Amonthly evaluation of liver function would be rea-sonable, and a variety of blood perimeters, such asa complete blood count, would seem reasonable.

Cyclosporin also has a place in the managementof psoriasis. With most physicians, this drug isreserved for patients who fail to respond to othertherapies. Close monitoring of renal function isvery important in these patients.

Acitretin is available, but patients must be mon-itored regularly for triglyceride levels while on thismedication. Hair loss has been reported. This isnot a drug for everyone. Acitretin is teratogenic,and should not be used in patients who canbecome pregnant.

What drives psoriasis?

T-lymphocytes drive psoriasis. How this occurs,however, is not accurately known. It appears thatthe keratinocyte and endophilial cell proliferationare secondary phenomenon.

The direction of therapy is aimed at the majorcells that are involved. Thus, the newer therapies(biological therapies) are aimed at T-lymphocytesand cytokines. Psoriasis is a major source of

research interest because itis a T-cell disease witheasy access and easy mon-itoring. For years, we havebeen targeting the ker-atinocyte with the use oftopical corticosteroids andother agents.

What role does genetics play?One-third of patients with psoriasis have a first-degree relative with psoriasis. If both parents areaffected with psoriasis, there is a 65% chancethat it will develop in their child. It is thought thatgene therapy is unlikely, but it may identifypatients most likely to respond to therapy.

What are the trigger factors?All of us who treat psoriasis know that stress isa trigger in many patients with psoriasis. A pre-ceding history of streptococcal infection, asillustrated in the case presentation, may alsotrigger the condition. Alcohol can be a con-tributing factor, and it has recently been foundthat smoking, can trigger the condition, espe-cially in pustular psoriasis. Trauma to the skin

Psoriasis

108 The Canadian Journal of CME / November 2003

If both parents are affectedwith psoriasis, there is a65% chance that it willdevelop in their child.

Psoriasis

110 The Canadian Journal of CME / November 2003

(the Koebner phenomenon) is well-known inpsoriasis.

Some drugs have been known to trigger pso-riasis, including lithium and beta blockers.

Other drugs that can be implicated in psoria-sis include angiotensin-converting enzymeinhibitors, non-steroidal anti-inflammatories,iodine, digoxin, and clonidine.

What are the breakthroughs? This is a very exciting time for the research andtreatment of psoriasis. Immunotherapy targetingthe lymphocyte is very encouraging. Anti-tumour necrosis factor alpha (TNF) therapy isvery exciting. Drugs (such as alefacept) andTNF blockers (such as infliximab and etaner-cept) are showing great promise. Patients withextensive disease are showing amazing respons-es to these new drugs. It’s important for physi-cians to make these patients aware that clinicaltrials are available, and patients can be involvedin the trials if they wish to be.

Apart from research breakthroughs andimmunotherapy, there are ongoing projects thatinvolve lasers and photodynamic therapy whichmay help our psoriasis patients.

In closing ...It is important to keep in mind that suboptimal dis-ease management in psoriasis and high relapserates of the condition contribute and add to patientfrustration. A better understanding and communi-cation between psoriasis patients and physicianswill improve clinical outcomes.

www.stacommunications.com

For an electronic version of this article, visit:The Canadian Journal of CME online.

Quick statistics concerning psoriasis:

• There are about 26,000 new cases of psoriasis in Canada every year.

• The average age of onset is 31.

• About 2% of the Canadian population is affectedby psoriasis.

• Suicide has been contemplated by 10% ofpatients.

• At least 10% of patients have diffuculties performing duties at work.

Take-homemessage

Net Readings

1. The National Psoriasis Foundation:www.psoriasis.org

2. Psoriasis Society of Canada:www.psoriasissociety.org

CME