Dr Tom Poyner explains how guidelines on the treatment of psoriasis could promote shared care to the benefit of patients


   

Psoriasis is a common skin disease, affecting approximately 2% of the population. There is no cure and the majority of patients have a rash at any one time. Although the disease has a significant impact on patients' lives, many receive minimal or suboptimal therapy. Most patients have mild disease, but there is evidence of marked variability within individuals with time.1

Many of those with mild-to-moderate psoriasis are managed in primary care, while those with extensive or difficult disease are usually under secondary care.

If guidelines are systematically developed statements to assist the practitioner in decisions about appropriate healthcare for specific clinical circumstances, they should be helpful in caring for patients with psoriasis.2 It is known that GPs would like regularly updated dermatological guidelines.3

If we are going to have guidelines for psoriasis, it is essential that they are valid, reproducible, reliable, representative and cost-effective.4 Certainly they should be clinically applicable, flexible, clear, reviewable and amenable to clinical audit.4

National guidelines

The first UK national guidelines for the care of patients with psoriasis appeared in the BMJ in 1991.5 This excellent document soon became dated, however, as vitamin D derivatives appeared in the same year. They were a clean, effective remedy for patients with mild-to-moderate psoriasis long term in primary care.6

The Therapy Guidelines and Audit Subcommittee of the British Association of Dermatologists therefore set about updating the 1991 guidelines. I must declare an interest in that I contributed to the section on recommendations for initial management.

In 1997 the document 'Current management of psoriasis' was published in the Journal of Dermatological Treatment.7 However, even the publication of this document was not without controversy. An accompanying editorial was entitled 'Guidelines or straightjacket?'8

Important areas covered

The current guidelines cover the following areas:

  • Clinical features of psoriasis
  • The impact of psoriasis on quality of life
  • Recommendations for initial treatment
  • Content of referral letters
  • Topical treatments
  • Systemic treatments

How far to take treatment

Patients are very variable in how far they wish to go with treatment. Many do not wish to have any treatment, while others want only to be clear of the rash for some special occasion. Some want to work at having no rash, or at best minimal rash all the time.

Guidelines for topical therapy

Topical therapies are effective, acceptable and easily available from primary care. There is a need to inform the GP in the guidelines of suitable treatments for each site, along with the benefits and risks.

While tar has been used for many years without any recorded serious side-effects, some work has highlighted theoretical risks.9

Dithranol is effective but requires significant patient education, and this is an area which guidelines do cover.

Vitamin D analogues are now a first-line therapy for psoriasis in primary care, but their rapid development means that guidelines need constant updating.

Topical retinoids have now appeared on the scene and again are an area that guidelines need to cover. It has been suggested that guidelines should have a 'Kite marking', regarding relevance, validity, evidence-base, usefulness, authors, sponsors and date of production.10

Topical steroids

Topical steroids are a cosmetically acceptable therapy, but inappropriate use can lead to local side-effects, e.g. thinning of the skin. There are therefore guidelines on their use for patients with psoriasis. These include:7

  • No topical treatment should be used for more than four weeks without critical review
  • Potent corticosteroids should not be used regularly for more than seven days
  • No unsupervised repeat prescriptions should be made; patients should be reviewed every three months
  • No more than 100g of a moderately potent or higher potency preparation should be applied per month
  • Attempts should be made to rotate topical corticosteroids with alternative non-corticosteroid preparations
  • Very potent or potent preparations should only be used under dermatological supervision.

It is debatable whether the guidelines for using topical steroids should be disease- or drug-orientated. The use of potent topical steroids on the face or flexures is not recommended.

However, a potent topical steroid might be used when treating scalp psoriasis in primary care, and some may think that the suggested review is excessive.

Phototherapy

Phototherapy and photochemotherapy are both very effective. Guidelines need to make the carer aware of both the benefits and the long-term risks of these therapies.

Broad-band phototherapy formed part of the traditional Ingram's regimen of tar baths, ultraviolet radiation B (UVB) and dithranol.

Narrow-band UVB is more effective than broad-band UVB, and if properly supervised could be delivered in the community.

The question is not one of efficacy but of safety. Photochemotherapy using psoralens with long-wave ultraviolet radiation A (PUVA) is unlikely to look so attractive outside dermatology departments. There is the risk of skin ageing and the increased risk of skin cancers. Psoralens is also an unlicensed drug.

Oral therapies

It is very easy to start a patient on a systemic therapy such as cyclosporin or acitretin, but far harder to stop it. Because retinoids are highly teratogenic, they are only prescribed in secondary care. However, GPs are more involved in the contraceptive advice to patients than dermatologists, and obviously there has to be some sharing of patient care.

Methotrexate is used for patients with an extensive rash, although there can be haematological and hepatic side-effects. Because of the risk of side-effects, therapy needs close monitoring, with regular haematological and biochemical checks. Primary care may become involved in this monitoring.

There is also the need to avoid certain medications such as trimethoprim, which can produce drug interactions with methotrexate. Guidelines need to cover these points.

The dialogue on who prescribes expensive agents such as cyclosporin can be divisory between primary and secondary care, and needs to be covered in local guidelines.

Future guidelines

Key components of useful clinical guidelines should be a review of the relevant, valid evidence on the benefits, risks and costs of alternative decisions.11 Future national guidelines will need to comment on the comparative efficacy and acceptability of different treatments.

While the present guidelines were well developed, they have not yet been disseminated outside the confines of dermatology departments. Certainly they could be used as a template for developing local guidelines. Only by creating the feeling of involvement can one hope to implement guidelines to improve patient care.

Local guidelines

Dr Andrew Warin has pioneered the development and implementation of local dermatological guidelines for GPs in his locality.12 Since 1985 there have been local guidelines on the care of dermatology patients in Exeter.

Local guidelines for GP referrals in dermatology have also been developed by the London Dermatology Planning Group in conjunction with GP colleagues and patient groups.13

In my own area we have seen guidelines developed which cover the treatment of scalp, guttate and plaque psoriasis.14 These guidelines are intended to help GPs manage common skin disorders. They are presented as small loose-leaf pages in a ring binder. This is a simple and easily accessible format; however, there is no mention from where the evidence is drawn.11

Local guidelines should be clear and concise. They could be on a single sheet of paper or in an electronic format. It is useful if there is a master document, from which they are derived, enabling one to ascertain whether the guidelines deviate from national guidelines and why.

Local guidelines should have a major interactive role, advising on what treatment to implement if the patient relapses, when to re-refer and with what level of urgency.

The responsibilities of primary and secondary care need to be clearly defined. The role of the nurse is expanding in both primary care and dermatology departments. Guidelines appear to be a tool that facilitates both this expansion and delegation of care from a doctor's hands, without detriment to the patient.

Audit

There has been a formal multicentre audit, based on published guidelines for the treatment of psoriasis in secondary care.15 Primary care should also audit the care of patients with psoriasis.

Possible areas are:

  • Type of medication
  • Quantity of medication
  • Frequency of review.

There is considerable variation in dermatological referral rates between GPs. Guidelines may lead to a general improvement in the standards of care and a more equal sharing of services by primary care. While guidelines will never replace dermatological education, they do focus our minds on providing a comprehensive evidence-based service for patients with psoriasis.

References

  1. Nevitt GJ, Hutchinson PE. Psoriasis in the community: prevalence, severity and patients' beliefs and attitudes towards the disease. Br J Dermatol 1996; 135: 533-7.
  2. Field MJ, Lohr KN. Clinical Practice Guidelines: direction of a new agency. Washington DC: Institute of Medicine, 1990.
  3. Herlow ED, Burton JL. What do general practitioners want from a dermatology department? Br J Dermatol 1996; 134: 313-18.
  4. Implementing Clinical Practice Guidelines. Can Guidelines be Used to Improve Clinical Practice? Effective Health Care 1994; 8: 1-12.
  5. Workshop of the Research Unit of the Royal College of Physicians of London, the Department of Dermatology, University of Glasgow, and the British Association of Dermatologists. Guidelines for the management of patients with psoriasis. Br Med J 1991; 303: 829-35.
  6. Poyner TF, Hughes JW, Dass BK et al. Long-term treatment of chronic plaque psoriasis with calcipotriol. J Dermatol Treat 1993; 4:173-7.
  7. Current management of psoriasis. J Dermatol Treat 1997; 8(1): 27-55.
  8. Guidelines or straightjacket? (Editorial). J Dermatol Treat 1997; 8(1): 1.
  9. Van Schooten FJ, Moonen EJ, Rhijnsburger E et al. Dermal uptake of polycyclic aromatic hydrocarbons after hairwash with coal tar shampoo. Lancet 1994; 344: 1505-6.
  10. Hibble A, Kanka D, Pencheon D. Guidelines in general practice. i 1998; 317: 862-3.
  11. Jackson R, Feder G. Guidelines for clinical guidelines. Br Med J 1998; 317: 427-8.
  12. Warin AP. How can we meet the dermatological needs of the community? Primary Care Dermatology Society Bulletin, Summer 1998.
  13. Robin Russell-Jones. Guidelines for GP Referrals in Dermatology. Beckenham: Magister, 1998.
  14. Guidelines for Skin Treatment. City Hospitals Sunderland, North Durham Acute Hospitals, South Tees Acute Hospitals Trust.
  15. Bilsland DJ, Rhodes LE, Zaki I. PUVA and methotrexate therapy for psoriasis: how closely do dermatology departments follow treatment guidelines? Br J Dermatol 1994; 131: 220-5.

Guidelines in Practice, December 1998, Volume 1
© 1998 MGP Ltd
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