Dr Rebecca Mawson shares some key points for managing psoriasis in primary care and how to screen for psoriatic arthritis

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Read this article to learn more about:

  • available treatments for psoriasis
  • when patients should be referred to secondary care.

T his article on psoriasis management is taken from a combination of sources, including NICE Clinical Guideline (CG) 153 on Psoriasis: assessment and management1 and the Scottish Intercollegiate Guidelines Network (SIGN) Guideline 121 on Diagnosis and management of psoriasis and psoriatic arthritis in adults.2 The article focuses on primary care management only and therefore does not cover phototherapy, oral retinoids, methotrexate, or cyclosporin.

1 Make the correct diagnosis

Psoriasis is a chronic inflammatory skin condition, which has a prevalence in the UK of 1.3–2.2%. Males and females are affected equally. Chronic plaque psoriasis is the most common type, affecting approximately 90% of people with psoriasis.3

Psoriasis is characterised by scaling and epidermal thickening. Classically, psoriasis lesions are bright red in colour, with clearly defined borders and silvery scaling which is easily removed. The lesions are usually symmetrical and commonly affect the scalp and extensor surfaces, such as elbows, knees, sacral area, and lower legs.3

It is important to examine the patient's entire body, focusing on the scalp, nails, and joints. Be aware that patients might feel uncomfortable disclosing genital involvement, for fear of stigma and embarrassment. When examining the patient, consider differential diagnoses including eczema, tinea, lichen planus, and lupus erythematosus.3

2 A good emollient is the cornerstone of psoriasis management

There is little evidence of superiority among the different emollients that are available, but patient preference will improve compliance, which is one of the barriers to effective therapy. Emollient therapy will maximise the skin's ability to function normally and to absorb and repair itself after irritant topical therapies have been applied. The emollients make the skin more comfortable and soften scales and plaques to allow better absorption of products such as vitamin D analogues and tar. Box 1 (see below) shows available emollients and their uses.

Box 1: Emollients and their uses4

Available emollients include:

  • lotions
    • water-based and tend to be very runny and easy to apply
    • cooling but not effective at moisturising very dry skin
    • useful for maintaining good skin once the psoriasis has gone
  • creams
    • thicker and greasier than lotions, but still easy to use
    • less runny and tend to come in pots or pump dispensers
    • usually the best option for day-to-day use
  • ointments
    • best moisturisers to use but unpleasant as they are very greasy and thick
    • oil-based rather than water-based
    • best option for very dry skin.
Adapted from the Psoriasis Association website. Moisturising. www.psoriasis-association.org.uk/pages/view/about-psoriasis/treatments/moisturising (accessed 15 November 2015) Reproduced with permission

3 Know the basics of common topical therapies

While adequate emollient therapy may be enough to treat mild psoriasis, a step up in treatment might be needed. Figure 1 (see below) shows the suggested treatment pathway for managing psoriasis.

Figure 1: Treatment pathway for psoriasis management
Treatment pathway for psoriasis management

NICE recommends topical therapy as first-line treatment, with initial use of daily potent steroid treatment and daily calcipotriol for plaque psoriasis. The steroid helps to manage the irritant side-effects of the calcipotriol as well as inflammation within the skin. Using separate preparations allows easy tapering down of the steroid. A combination product that combines steroid and vitamin D analogue is available. This helps compliance, but can lead to steroid over-exposure, as it may be difficult to titrate. See Table 1 (see below) for a list of psoriasis treatments.

Table 1: Treatments for psoriasis3
DrugMode of action
Emollients Reduce dryness, scaling, and cracking; provide barrier against irritant or causative factors
Steroids Anti-inflammatory properties give rapid control but side-effects occur with long-term use
Vitamin D analogues Affect cell division and differentiation; can cause irritation and inflammation
Coal tar Anti-inflammatory properties; can be used safely on normal skin, mild irritation may occur; strongly scented
Dithranol Unknown mechanism but works for chronic plaque psoriasis; messy and stains clothes
Tazarotene (retinoid) More irritating and less effective than vitamin D analogues; can be used for mild to moderate disease affecting <10% of the body
Salicylic acid Keratolytic properties that are good for thick plaques but it needs to be used after a softening agent such as emollient or oils

4 Problem areas

One of the challenges of psoriasis management can be when it affects areas that might be unresponsive to or irritated by treatment, or when there are barriers to skin such as hair and nails. Table 2 (see below) shows some of the areas that can be affected by psoriasis and the different treatment options that are available.

Table 2: Areas affected by psoriasis and treatment options
Site Click image to view full size IssuesTreatment options
Flexoral Flexoral psoraisis
  • Can easily be mistaken for fungal infections but does not respond to antifungal agents

Moderate potency topical steroid (e.g. betamethasone cream/ointment) short term for maximum of 2 weeks

If ineffective try vitamin D analogue or tacrolimus for 4 weeks; refer to secondary care if not effective

Nails Nail psoraisis
  • Topical agents do not absorb readily through thick keratin

Very difficult to manage in primary care; refer for secondary care treatment

Genital Genital psoraisis
  • Skin around these areas is thin and easily affected by topical steroids

Emollient therapy plus a mild/moderate steroid

Palms and soles Palms and soles psoraisis
  • Topical agents do not readily absorb through the thickened stratum corneum of the palms and soles

Emollients under occlusion overnight might help but often referral to secondary care is needed

Guttate Guttate psoriasis
  • Can occur suddenly and can be distressing for patients; does not respond to usual psoriasis management

Same as plaque psoriasis but refer early for phototherapy if failure to respond

No firm evidence to support the use of antibiotics or tonsillectomy in the management or prevention of guttate psoriasis after streptococcal sore throat

RD=ready diluted.Images from DermNet NZ (www.dermnetnz.org) reproduced with permission.

5 Know your potions, lotions, and shampoos

NICE CG153 recommends that:1

  • creams, lotions, or gels are suitable for widespread psoriasis
  • lotions, solutions, or gels are suitable for the scalp or hair-bearing areas
  • ointments are suitable for treating areas of skin with thick scaling.

For thick scaly scalp plaques, apply a softening agent such as emollient, arachis oil (beware of peanut allergy), coconut oil, or olive oil directly to parted hair. Use a comb to remove plaques. Leave on overnight if tolerated. Use a tar-based shampoo to wash it out.

For inflamed scalp plaques, soften and remove plaques as previously described. Use a steroid shampoo and massage it into a dry scalp. Leave it in for 15 minutes then wash it out. It is recommended that steroid shampoo is used for a maximum of 4 weeks. However, there is currently no evidence that longer-term use will cause harm.

6 When to refer

Patients should be referred to secondary care if:1

  • there is a new presentation of the disease in patients under 18 years
  • the psoriasis covers >10% of the body
  • there is nail involvement that
    • affects the function of the nail or
    • is cosmetically distressing
  • the patient is not responding to topical treatment
  • the psoriasis is seriously affecting the patient's physical, psychological, or social wellbeing
  • there is diagnostic uncertainty
  • the patient has acute guttate psoriasis needing phototherapy
  • the patient is experiencing joint involvement.

NICE CG153 recommends the use of the Psoriasis Area and Severity Index (PASI) in adults with psoriasis,1 which involves both the doctor and patient independently rating the psoriasis in terms of severity, surface area affected, and high-impact areas. Table 3 (see below) shows some very rare dermatological emergencies to be aware of.

Table 3: Dermatological emergencies
Erythrodermic psoriasisGeneralised pustular psoriasis
Erythrodermic psoriasis Generalised pustular psoriasis
  • Redness and shedding of the whole skin.
  • Characterised by multiple sterile non-follicular pustules within plaques of psoriasis. It is rare and may be associated with a fever.
Action: acute admission for rehydration and fluid management. Action: same-day referral to dermatology for outpatient management.
Images from DermNet NZ (www.dermnetnz.org) reproduced with permission.

7 Do not miss psoriatic arthritis

Psoriatic arthritis is underdiagnosed and sometimes forgotten in primary care, with much focus being placed on rheumatoid arthritis. It is estimated that only 4% of patients with psoriatic arthritis have commenced treatment.6 It is an important pathology to remember when reviewing patients with this skin disease, as 10–30% of them will develop associated arthritis.5

There may be a 10-year time lag between skin changes and arthropathy. In comparison with rheumatoid arthritis, it has a predilection for distal interphalangeal joints, especially in the presence of a nail disease. There is a useful primary care screening tool, called the Psoriasis Epidemiological Screening Tool (PEST), which might be used when patients attend an annual psoriasis medication review (see Box 2, below).6

Box 2: Psoriasis Epidemiological Screening Tool for annual psoriasis medication review6

The PEST Questionnaire

  • Have you ever had a swollen joint (or joints)?
  • Has a doctor ever told you that you have arthritis?
  • Do your finger nails or toe nails have holes or pits?
  • Have you had pain in your heel?
  • Have you had a finger or toe that was completely swollen and painful for no obvious reason?

Each 'Yes' answer scores 1 point. A score of >= 3 is indicative of psoriatic arthritis. (Sensitivity = 0.92, specificity = 0.78)

Adapted from: Ibrahim G, Buch M, Lawson C et al. Evaluation of an existing screening tool for psoriatic arthritis in people with psoriasis and the development of a new instrument: The Psoriasis Epidemiology Screening Tool (PEST) questionnaire. Clin Exp Rheumatol 2009; 27: 449–474. Reproduced with permission

8 Look deeper than the skin

As with all dermatological conditions, the severity of the disease is not always proportional to its psychological impact. The Psoriasis Association has published information raising the issue of mental health problems in people with the condition.7 SIGN 121 suggests using a dermatology life quality index (DLQI) to assess the impact on patients' quality of life. In practice, however, this might not be appropriate, but the ideas are useful when trying to contextualise the impact on the patient. Approximately one-third of people with psoriasis experience depression and 10% contemplate suicide.7

9 Consider co-morbidities

Psoriasis is a systemic inflammatory disease that causes vascular endothelial dysfunction. This leads to an increased risk of heart disease, hypertension, stroke, and metabolic syndrome plus many more inflammatory conditions. Patients with psoriasis are more likely to be obese, have diabetes, or smoke.8

General Practitioners are ideally placed and skilled for risk-factor assessment and modification, including:

  • smoking cessation
  • alcohol reduction
  • lipids and diabetes checks
  • annual blood pressure checks.

There is also increased risk of chronic kidney disease in patients with severe psoriasis, independent of traditional causes, especially younger patients.9 To reduce cardiovascular risks, patients with psoriasis should have their blood pressure closely managed.10

10 Patient resources

Psoriasis is a chronic disease, which remits and returns. It is essential to give the patient support and education about how to manage flares. There are useful resources on the internet that can help with patient education and engagement:

  • The Psoriasis Association (www.psoriasis-association.org.uk) offers advice and education for people with psoriasis. The website includes useful podcasts and advice from dermatology nurses
  • The Psoriasis and Psoriatic Arthritis Alliance (www.papaa.org) offers advice, education, and self help for people with psoriasis and arthritis
  • The British Association of Dermatologists (www.bad.org.uk) advises on best practice and the provision of dermatology services in the UK; PASI and DLQI forms can be found on the website (www.bad.org.uk/healthcare-professionals/psoriasis).

References

  1. NICE. Psoriasis: assessment and management. Clinical Guideline 153. NICE, 2012. Available at: www.nice.org.uk/guidance/cg153
  2. Scottish Intercollegiate Guidelines Network. Diagnosis and management of psoriasis and psoriatic arthritis in adults. SIGN 121. Edinburgh, SIGN, 2010. Available at: www.sign.ac.uk/guidelines/fulltext/121/index.html
  3. Ashton, R. Leppard B. Differential diagnosis in dermatology. 3rd edn. CRC Press, 2005.
  4. The Psoriasis Association website. Moisturising. www.psoriasis-association.org.uk/pages/view/about-psoriasis/treatments/moisturising (accessed 15 November 2015).
  5. Lenman M, Abraham S. Diagnosis and management of psoriatic arthropathy in primary care. Br J Gen Pract 2014; 64 (625): 424–425.
  6. Ibrahim G, Buch M, Lawson C et al. Evaluation of an existing screening tool for psoriatic arthritis in people with psoriasis and the development of a new instrument: The Psoriasis Epidemiolog y Screening Tool (PEST) questionnaire. Clin Exp Rheumatol 2009; 27: 469–474.
  7. Psoriasis Association. See psoriasis: look deeper. London: Psoriasis Association, 2012. Available at: www.psoriasis-association.org.uk/silo/files/SPLD-Report-_FINAL-1.pdf
  8. Barraclough C, Clark S. Psoriasis and cardiovascular risk assessment in primary care. Br J Gen Pract 2015; 65 (638): 476–476.
  9. Wan J, Wang S, Haynes K et al. Risk of moderate to advanced kidney disease in patients with psoriasis: population based cohort study. BMJ 2013; 347: f5961.
  10. Fernández-Torres R, Pita-Fernández S, Fonseca E. Psoriasis and cardiovascular risk. Assessment by different cardiovascular risk scores. J Eur Acad Dermatol Venereol 2013; 27 (12): 1566–1570. G