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Psoriasis is a common skin disease, affecting around 2% of the population.1 It is a persistent, relapsing condition causing significant impairment to the patient's quality of life. Psoriasis can develop at any age, but is uncommon in children. The majority of cases occur before 35 years of age.1 Both sexes are affected equally and there is a positive family history in some patients.2 A significant proportion of people with psoriasis have associated joint disease (reported to be around 14% in one study).1
A number of factors are believed to affect the onset of or exacerbate psoriasis, including:3
- excessive alcohol intake
- psychological stress
- certain drugs (e.g. antimalarials, beta blockers, lithium, non-steroidal
- streptococcal infection (strongly associated with guttate psoriasis).
The healthcare practitioner should base the diagnosis of psoriasis on clinical findings, and take into account: distribution; number, size, colour, and shape of lesions; surface features (smooth, scaly, or pustular); involvement of other areas such as joints or nails.3 Examples of some of these presentations can be viewed on p.2 (see Figure 1, images 1–4). Further images are available at: www.dermnet.com
Types of psoriasis
The NICE clinical knowledge summary on psoriasis (see cks.nice.org.uk/psoriasis#!diagnosissub) provides a useful guide to the different types of psoriasis and how these may present.
Chronic plaque psoriasis (see Figure 1, image 2) is the most common type, affecting 80%–90% of individuals with psoriasis.2 This may present as a single lesion up to a large number of them, and often occurs on the scalp, trunk, buttocks, and extensor surfaces. Lesions range from 1 cm to several centimetres in diameter and scale is present.3 Other types of psoriasis include the following:
- scalp psoriasis—this is usually chronic plaque psoriasis and can affect the whole scalp3
- palmo-plantar (pustular or hyperkeratotic) psoriasis (see Figure 1, image 3)—this can be localised (involving the palms and soles) or generalised, which is less common but requires same-day hospital referral3
- nail psoriasis—this is particularly common in individuals with psoriatic arthritis (90% of whom have nail changes)3
- guttate psoriasis (see Figure 1, image 1)—lesions present as small scaly papules (up to 1 cm in diameter)3
- erythrodermic psoriasis—this is where psoriasis is so diffuse it can affect more than 90% of the body; it requires same day hospital referral3
- psoriatic arthropathy (see Figure 1, image 4)—as soon as psoriatic arthritis is suspected, the person should be referred to a rheumatologist for assessment.1,3
When to refer to secondary care
In our locality, most referrals to dermatology services are triaged by an experienced GPwSI in Dermatology through the Choose and Book system. The GP should consider referring the patient to secondary care in these situations:
- diagnostic uncertainty
- failure of topical therapy
- extensive disease
- psoriasis covering more than 30%–40% of the body surface
- severe psychological or social impact or impact on quality of life
- psoriatic arthropathy (referral to rheumatologist)
- acute unstable psoriasis (urgent referral) and erythrodermic or rarely generalised pustular psoriasis (emergency referral).
Management of psoriasis
In its first clinical guideline on the assessment and management of psoriasis (NICE CG153, published in October 2012; see www.nice.org.uk/CG153), 1 NICE advises GPs and other healthcare professionals to assess the impact that psoriasis has on the physical, psychological, and social wellbeing of their patients, in addition to checking for the presence of psoriatic arthropathy. Doctors are recommended to conduct these assessments when they first see their patients, before they refer patients to specialists, and when monitoring how patients are responding to treatments. This is difficult to achieve in the 10 minutes currently allocated to each patient consultation.
Most cases of psoriasis are mild and can be treated in general practice either by the GP or GPwSI. In our locality, experienced GPwSIs play a major role in triaging and seeing patients and are involved in the education of GPs and trainees. Unfortunately, there is no cure for psoriasis, but there are effective suppressive treatments aimed at inducing remission or controlling symptoms.4 Watchful waiting or no active treatment may be appropriate for patients with mild, long-standing disease and who have accepted their condition. Management of psoriasis in primary care is variable—diagnosis is often delayed, with a lot of patients being treated as having eczema. Education is crucial for improving diagnosis; the author’s hospital and community GPwSIs play a major role in dermatology training with the support of local consultants, who conduct mentoring clinics with the GPwSIs and arrange educational evenings for the GPs.
Assessing severity and impact
The Psoriasis Area and Severity Index (PASI) is a validated tool that measures disease severity in adults with severe chronic plaque psoriasis (see: bit.ly/medicareAUS-PASI).3
Measuring quality of life across all skin disease can be carried out by the Dermatology Life Quality Index (DLQI) validated tool (for adults) or the Children’s Dermatology Life Quality Index (CDLQI).1 A score of >10 (range 0–30) has been shown to correlate with at least ‘a very large effect’ on an individual’s quality of life.5
The British Association of Dermatologists (BAD) and the Primary Care Dermatology Society (PCDS) guideline on the management of psoriasis recommends that patients are given both verbal and written information on treatment options.4 Likewise, NICE CG153 recommends that support and information should be tailored to suit individuals so that they confidently understand their diagnosis and treatment options.1 For some useful support groups, see Box 1.
The clinician and patient should make a joint decision about the various therapeutic options, paying particular attention to the effect of psoriasis on quality of life and the benefits and risks of treatment.4 Educating the patient about their condition is a crucial part of management. The initial decision revolves around whether to employ topical therapy, systemic therapy, or both.
Box 1: Support groups
Healthcare professionals may find it useful to provide patients with information about the following support groups:
- The Psoriasis Association
7 Milton Street, Northampton NN2 7JG
Tel: 08456 760076 or 01604 251620
- Psoriasis and Psoriatic Arthritis Alliance
PO Box 111, St Albans, Herts, AL2 3JQ
Tel: 01923 672837
- DermNET NZ
- British Association of Dermatologists (BAD)
Willan House, 4 Fitzroy Square, London W1T 5HQ
Tel: 020 7383 0266
- British Skin Foundation
4 Fitzroy Square, London W1T 5HQ
Tel: 020 7391 6341
- British Society for Rheumatology (BSR)
Bride House, 18–20 Bride Lane, London EC4Y 8EE
Tel: 020 7842 0900
People with psoriasis should understand how to use prescribed treatments safely and effectively and when to seek further review. Treatment choice depends on individual patient characteristics, such as:
- general health
- social status (e.g. does the patient live alone or are they supported by a carer or family?)
- psychological impact of the disease
- severity of the disease
- location of affected body sites:
- lesions on hands, feet, and face may cause functional difficulties
- nails are very difficult to treat
- presence of arthritis
- any previous treatments.
People with psoriasis should be offered topical therapy as first-line treatment. Second-line therapy (i.e. phototherapy and systemic non-biologic agents) or third-line treatments (biologic therapy) may be offered at the same time as topical therapy if the latter is unlikely to provide adequate control.1 Recommended treatment order for the different types of psoriasis is summarised in the ‘management’ section of the NICE clinical knowledge summary for psoriasis (see cks.nice.org.uk/psoriasis#!management).3 A brief description of the different types of treatments is given below.
Almost all patients with psoriasis will need emollients and bath additives. There are many products available; therefore, patient preference and cost are important factors in choosing which one to prescribe.3,6,7
Vitamin D analogues
Vitamin D analogues (calcipotriol, calcitriol, and tacalcitol) can be used for most types of psoriasis and are the first choice for maintenance treatment. They are cosmetically acceptable to the patient but can take up to 6–8 weeks to work. They can also irritate the skin (particularly calcipotriol), especially on the face and flexural area.1 Systemic adverse effects are rare and include hypercalcaemia and parathyroid hormone suppression. The maximum recommended dosage should not be exceeded.8 Neither calcitriol nor tacalcitol is licensed for used in children aged under 12 years. The use of vitamin D analogues in pregnancy and breastfeeding is best avoided if possible.
Steroids are an acceptable and effective way of treating psoriasis but they carry risks with prolonged use, such as skin thinning, telangiectasia, hypopigmentation, and, in rare cases, systemic absorption; in addition, disease flare-up can occur on sudden withdrawal of the steroid.3,4,9 Topical corticosteroids are available in four potencies:
- mild (e.g. topical hydrocortisone)
- moderate (e.g. clobetasone butyrate)
- potent (e.g. betamethasone dipropionate, fluocinolone, mometasone)
- very potent (e.g. clobetasol propionate, diflucortolone valerate).
Only mild to moderate topical steroids should be used on the face and flexural areas, and for children.4 For very thick plaques, or on certain areas like the scalp, palms, and soles, a stronger topical steroid is needed.
For topical treatment of psoriasis affecting the trunk and limbs, NICE CG153 recommends that a potent corticosteroid is applied once daily plus vitamin D or a vitamin D analogue once daily (applied separately, one in the morning, the other in the evening).1 The patient should be reviewed after 4 weeks. If clearance, near clearance, or satisfactory control does not occur after a maximum of 8 weeks, vitamin D or a vitamin D analogue alone should be applied twice daily; if this is unsatisfactory, NICE recommends use of a potent corticosteroid twice daily or coal-tar preparation (once or twice daily).1
Tar-based preparations are a therapeutic option particularly suited to the treatment of scalp psoriasis;4 however, they have an unpleasant odour and can stain clothes. The choice of tar preparation should take into account the location of the affected skin, previous response to other treatments, and the patient’s preference. Tar products can be used alone or in combination with hydrocortisone, salicylic acid, dithranol, or sulphur.
Dithranol is generally only used for plaque psoriasis and in patients who have psoriasis that is resistant to other topical treatments; however, the use of these preparations requires strong motivation on the part of the patient due to staining and skin irritation. Generally used as a short-contact treatment (30–60 minutes), dithranol comes in concentrations from 0.1%–3% and can be very effective in a motivated patient.3 One effective treatment is Lassar’s paste—dithranol with salicylic acid and zinc oxide—which is applied to the plaque, covered by stockinette, and left on for 24 hours.
Tazarotene gel (0.05%–0.1%) is a treatment option for mild to moderate plaque psoriasis. This therapy is teratogenic and should not be used in pregnant women, women who are planning a pregnancy, those who are breastfeeding, and patients under the age of 18 years.6 Tazarotene can cause irritation, so patients need to avoid intense sunlight and to wash their hands after use.
Topical calcineurin inhibitors
These include tacrolimus ointment 0.1% and pimecrolimus cream 1%, which are particularly useful for treating psoriasis of the face and flexures, and in patients who develop topical steroids side-effects.9
A consultant dermatologist will usually supervise the use of ultraviolet phototherapy in the management of psoriasis. It is an effective treatment for guttate or plaque psoriasis that is resistant to topical therapy.1,4 There are two types of ultraviolet phototherapy:10,11
- PUVA, where psoralen is given two hours before UVA phototherapy
- UVB: broadband UVB with a wavelength of 290–320 nm; or narrowband UVB (NB-UVB) of 311–313 nm, which is now considered more appropriate.
Ultraviolet treatments are usually given 2 to 5 times a week (2 to 3 times a week for narrowband UVB).1 The main risk of phototherapy is the development of non-melanoma skin cancers.10 Localised phototherapy (e.g. excimer laser) can also be useful,9 but may cause skin pigmentation.
Patients who are considered eligible for systemic therapy will usually conform to the rule of tens, where the body surface area affected is >10%, or the PASI score is >10, or the DLQI is >10.12 This type of treatment is associated with significant short- and long-term side-effects, and is therefore usually initiated and followed up in secondary care.13
NICE CG153 recommends that methotrexate should be offered as the first-choice systemic agent for those who fulfil certain criteria.1 In practice, methotrexate is ideal in patients with arthritis but both methotrexate and acitretin are used in secondary care and some hospitals use ciclosporin. Methotrexate is taken in tablet form once weekly, sometimes in combination with folic acid once weekly to minimise some side-effects. The drug is teratogenic and so is contraindicated in pregnant women and in those of childbearing age and who are not using adequate contraception. In addition, it should be avoided in patients with severe renal failure, liver diseases, infectious diseases, or severe anaemia. Patients receiving methotrexate treatment require regular blood tests.14
Ciclosporin suppresses the immune system. NICE recommends changing from methotrexate to ciclosporin (or vice versa) when response to first-choice systemic treatment is inadequate.1 Ciclosporin is usually taken in capsule form twice daily. The main side-effects are hypertension, renal impairment, and increased risk of malignancies. Patients taking ciclosporin should have regular blood and urine tests, along with blood-pressure measurements.15
Acitretin (a retinoid) should be considered for adults if methotrexate and ciclosporin are not appropriate or have failed or for people with pustular forms of psoriasis.1 In many hospitals, it is used as first choice for nail psoriasis and psoriasis without arthritis. Oral acitretin is effective as monotherapy or in combination with PUVA (RePUVA). However, side-effects include dryness of the mouth, lips, and eyes, and use of the drug can lead to blood and bone abnormalities and hypertriglyceridaemia. Acitretin is not normally given to women of childbearing age.16
The use of biologic interventions in psoriasis has been covered in a guideline by BAD,5 and NICE has issued a number of technology appraisals on the use of specific biologic agents to treat psoriasis, including adalimumab, etanercept, infliximab, and ustekinumab,17-20 as well as golimumab for psoriatic arthritis.21 Many other biologic agents are in development. Both BAD and NICE recommend that biologic drugs are only to be used if the psoriasis has failed to respond to, or if the patient is intolerant of, conventional therapy (including systemic therapy and phototherapy), and when severe psoriasis is affecting quality of life (based on the PASI or DLQI).1,4 Treatment continuation should be dependent on response within a certain time period.17-21
Biologic agents do have a cost impact and their side-effects are not well known. It is important to ensure that all patients are registered with the BAD Biologic Interventions Register, which will assess safety issues in the relevant population.
Screening and treating comorbidities
Patients with psoriasis are at increased risk of coronary artery disease, inflammatory bowel disease (especially Crohn’s disease), diabetes, hypertension, depression, and lymphoma.22 It is important to screen for these diseases and to treat them; primary care is in an ideal position to maintain a low threshold for screening patients with psoriasis for these conditions. Lifestyle changes should be promoted, including stopping smoking, taking exercise, moderating alcohol intake, and maintaining a body mass index between 19 and 24.
Psoriasis is a systemic disease and is treated as such. As well as having the visible skin disease, patients are at risk of psychological and physical co-morbidities and side-effects from drug treatments; they also bear the social impact of the disease. Primary care teams have a pivotal role in managing the condition. Early diagnosis and targeted individualised treatment is crucial and can be achieved with help of community GPwSI and secondary care clinicians.
- NICE. Psoriasis: The assessment and management of psoriasis. Clinical Guideline 153. London: NICE, 2012. Available at: www.nice.org.uk/Guidance/CG153
- Meier M, Sheth P. Clinical spectrum and severity of psoriasis. Current Problems in Dermatol 2009; 38: 1–20.
- NHS Clinical Knowledge Summaries website. Psoriasis. www.cks.nhs.uk/psoriasis/management/scenario_diagnosis/diagnosis/pustular_psoriasis#-406348 (accessed 6 August 2014).
- British Association of Dermatologists, Primary Care Dermatology Society. Recommendations for the initial management of psoriasis. In: Guidelines—summarising clinical guidelines for primary care. 52nd ed. Berkhamsted: MGP Ltd, February 2014: 401–403.
- Smith C, Anstey A, Barker J et al. British Association of Dermatologists’ guidelines for biologic interventions for psoriasis 2009. Br J Dermatol 2009; 161 (5): 987–1019.
- British Association of Dermatologists website. Patient information leaflets (PILs). www.bad.org.uk/for-the-public/patient-information-leaflets/psoriasis (accessed 11 August 2014).
- Mason J, Mason A, Cork M. Topical preparations for the treatment of psoriasis: a systematic review. Br J Dermatol 2002; 146 (3): 351–364.
- Patient.co.uk website. Chronic plaque psoriasis. Topical therapy: vitamin D analogues. www.patient.co.uk/doctor/chronic-plaque-psoriasis (accessed 11 August 2014).
- Feldman S. Treatment of psoriasis. UpToDate website. Dellavalle R and Callis Duffin K (Eds). www.uptodate.com/contents/treatment-of-psoriasis (accessed 6 August 2014).
- British Association of Dermatologists website. Phototherapy. www.bad.org.uk/for-the-public/patient-information-leaflets/phototherapy (accessed 11 August 2014).
- British Photodermatology Group. British Photodermatology Group guidelines for PUVA. Br J Dermatol 1994; 130: 246–255.
- Finlay A. Current severe psoriasis and the rule of tens. Br J Dermatol 2005; 152 (5): 861–867.
- Griffiths C, Clark C, Chalmers R et al. A systematic review of treatments for severe psoriasis. Health Technol Assess 2000; 4 (40): 1–125.
- British Association of Dermatologists website. Methotrexate. www.bad.org.uk/for-the-public/patient-information-leaflets/methotrexate (accessed 11 August 2014).
- British Association of Dermatologists website. Ciclosporin. www.bad.org.uk/for-the-public/patient-information-leaflets/ciclosporin
(accessed 11 August 2014).
- British Association of Dermatologists website. Acitretin. www.bad.org.uk/for-the-public/patient-information-leaflets/Acitretin (accessed 11 August 2014).
- NICE. Etanercept and efalizumab for the treatment of adults with psoriasis. Technology Appraisal 103. London: NICE, 2006. Available at: www.nice.org.uk/guidance/TA103
- NICE. Infliximab for the treatment of psoriasis. Technology Appraisal 134. London: NICE, 2008. Available at: www.nice.org.uk/guidance/TA134
- NICE. Adalimumab for the treatment of psoriasis. Technology Appraisal 146. London: NICE, 2008. Available at: www.nice.org.uk/guidance/TA146
- NICE. Ustekinumab for the treatment of adults with moderate to severe psoriasis. Technology Appraisal 180. London: NICE, 2009. Available at: www.nice.org.uk/guidance/TA180
- NICE. Golimumab for the treatment of psoriatic arthritis. Technology Appraisal 220. London: NICE, 2011. Available at: www.nice.org.uk/guidance/TA220
- Scottish Intercollegiate Guidelines Network. Diagnosis and management of psoriasis and psoriatic arthritis in adults. SIGN, 2010. Available at: www.sign.ac.uk/guidelines/fulltext/121/index.html G