VOL: 99, ISSUE: 20, PAGE NO: 28
Janet Blake, RN.
Community Nurse, Kingston, Surrey
Psoriasis is a chronic skin disease, which affects around 2% of people in the UK (Nevitt, 1996). Both sexes are equally affected and it may appear for the first time at any age, although it is most likely between the ages of 11 and 45.
What is psoriasis?
Psoriasis is an acceleration of the usual skin replacement process. Usually it takes a skin cell 21 to 28 days to mature, during which time it reaches the surface and is shed as a dead cell. In people with psoriasis this process can take four days.
Some people appear to have a genetic tendency to psoriasis, which may be triggered by injury, infection, certain drugs and stress, both physical and emotional. Any area of the skin can be affected, including the nails. The most usual places are the knees, elbows and scalp.
Psoriasis and quality of life
Our skin has an important role in defining who we are. Psoriasis changes the appearance of the skin and marks people as different. A person with psoriasis may feel anger or sadness about their condition, which can affect relationships, careers and self-esteem.
Despite the number of treatment options available, 80% of patients suffering from psoriasis do not consult the medical profession (O’Neill and Kelly, 1996). This is surprising, since psoriasis can considerably undermine quality of life. It is also likely that doctors probably underestimate the psychological and social morbidity associated with psoriasis (O’Neill and Kelly, 1996).
Although there is no cure, most cases of psoriasis can be managed effectively. Psoriasis tends to be sporadic, and treatment responses vary between patients, and over time (Ashcroft et al, 2000).
The main aims of treatment are to minimise the severity of symptoms and reduce the impact of psoriasis on the patient’s quality of life (Gawkrodger, 1997).
Topical and systemic treatments
Treatments can be topical or systemic (see page 134). Topical treatments tend to be used when psoriasis affects less than 20% of the body’s surface. The decision to prescribe a systemic treatment is usually taken by a dermatologist and is based on the severity of the disease, together with social and psychological factors. Because of the toxicity of topical agents, strategies for dose-sparing may be considered, including:
- Maximising the use of topical therapy
- Using the lowest effective dose
- Using therapy intermittently.
Because conventional therapies do not offer a cure and are time-consuming, some patients may seek alternative remedies. Alternatives may include natural creams such as aloe vera, spring water, sea salts, thermal baths and acupuncture, based on anecdotal rather than clinical evidence.
Reducing stress may help improve psoriasis, and some patients find value in stress-management classes, relaxation training, yoga, massage, aromatherapy or reflexology.
Community nurses should ensure patients are reviewed regularly: the condition tends to vary in severity and the efficacy of treatment can alter over time.
Factors which can aggravate psoriasis include stress, infection, trauma and dry skin. Smoking and alcohol may trigger or exacerbate it, so patients should be encouraged to give up or cut back.
Patients require ongoing education. A community survey (O’Neill and Kelly, 1996) found that 54.9% of people with psoriasis wanted more information about the disease, and 69% specifically about treatments.
Patients’ records should be checked to ensure that no medication is exacerbating the condition, for example, ACE inhibitors, beta-blockers, lithium and hydroxychloroquine (Pardasani et al, 2000).
Talking to patients
Areas for discussion with patients include:
- How does psoriasis affect the patient’s lifestyle, including relationships and work?
- Is treating the visible areas a priority?
- How much effort and time is the patient willing to invest in compliance with therapy?
- Does the patient know about a proposed therapy’s possible side-effects and how long it might take to achieve visible results?
Psoriasis is mainly a community-managed disease and primary care nurses can play a valuable role. However, some nurses have said that they require further training to manage and educate patients (Cox and Bowman, 2000).
TYPES OF PSORIASIS
There are several subtypes of psoriasis (Pardasani et al, 2000):
- Plaque-type psoriasis, the commonest form, presents as red, thick lesions covered in a silver scale
- Guttate psoriasis presents as numerous, small, oval-shaped lesions. These emerge, usually on the trunk, after acute upper respiratory tract infections. The plaques are neither as scaly nor as red as plaque psoriasis. It often affects children and younger people
- Localised pustular psoriasis presents as either discrete papules or plaques that express pustules on their surface. In many cases it emerges on the palms or soles, a condition called palmoplantar pustular psoriasis
- Generalised pustular psoriasis affects a larger area, sometimes even involving the entire body
- Erythrodermic psoriasis causes patients to have severe, generalised erythema and scaling that can involve the whole body
- Scalp psoriasis usually presents as thick, patchy scales and redness on the scalp. Patients may complain of severe itching and tightness of the scalp
- Flexural psoriasis is found in the armpits, groin, under the breasts and in other skins folds
- Around 5-7% of people with psoriasis develop psoriatic arthropathy which affects the interphalangeal joints
- Emollients: these moisturise the skin. Are applied directly to the affected areas or used in the bath or shower. May be all that is required in mild psoriasis. May need to be applied three times a day to be effective
- Coal tar-based products: have been used for many years. Beneficial where there is severe itching. Tend to have a strong smell, stain clothing and can be messy to use. Not generally recommended for delicate areas such as the face
- Dithranol: used to treat well-defined plaques of psoriasis. Can cause severe irritation if it comes into contact with non-psoriatic skin; usually applied for short periods of time and then washed off. Can stain clothes
- Vitamin D analogues: such as calcitriol and calcipotriol work by reducing inflammation. They are odourless and do not stain or mark clothing
- Keratolytics: these help remove scales. The most common is salicylic acid - used on the scalp and areas of thick scaling such as the soles of the feet and palms of hands. Salicylic acid should not be used with phototherapy as it acts as a sunscreen and blocks out the therapeutic light
- Topical retinoids: vitamin A derivatives, such as Tazarotene, help reduce inflammation. Patients should be told to expect a reddening of the plaques at the start of treatment, which is part of the normal healing process
- Topical corticosteroids: these vary from 1% hydrocortisone (very mild) to 0.05% clobetasone proprionate (very potent). Their anti-inflammatory properties reduce inflammation, scaling and itching. Tolerance can develop and patients may relapse rapidly once treatment is stopped.
- Phototherapy: this involves using ultraviolet light as an anti-inflammatory to treat psoriasis. There are two types - PUVA (the oral drug psoralen plus ultraviolet A), and UVB (ultraviolet B). Phototherapy tends to be used for patients who do not respond to topical treatments or those with diffuse psoriasis in whom topical treatments would be impractical. It is usually administered in an outpatient dermatology department.
- Methotrexate: this is an antimetabolite, also used for cancer and is licensed for use in severe psoriasis unresponsive to topical and phototherapies. It is contraindicated in pregnancy and during lactation. Side-effects include hepatotoxicity, nausea, abdominal pain and fatigue. Improvement may be seen within 48 hours
- Oral retinoids: these are vitamin A derivatives, such as acitretin, and may be prescribed for severe and extensive psoriasis, which is resistant to other forms of treatment. Side-effects include teratogenicity, dryness of mucous membranes, skin and conjunctiva
- Ciclosporin: a potent immunosuppressant licensed for severe psoriasis where conventional therapy is ineffective or inappropriate. Because of its toxicity, ciclosporin requires close hospital supervision.
Source: Hutchinson et al, 2000; Kowalzick, 2001; Gawkrodger, 1997.
Ashcroft, D.M., Li Wan Po, A., Williams, H.C. et al. (2000) Systematic review of comparative efficacy and tolerability of calcipotriol in treating chronic plaque psoriasis. British Medical Journal 320: 963-967.
Cox, N.H., Bowman, J. (2000)An evaluation of educational requirements for community nurses treating dermatological patients. Clinical and Experimental Dermatology 25: 1, 12-15.
Gawkrodger, D.J. on behalf of the British Association of Dermatologists. (1997)Current management of psoriasis. Journal of Dermatological Treatment 8: 27-55.
Hutchinson, P.E., Marks, R., White, J. (2000)The efficacy, safety and tolerance of calcitriol 3?g/g ointment in the treatment of plaque psoriasis: a comparison with short-contact dithranol. Dermatology 201: 2, 139-145.
Kowalzick, L. (2001)Clinical experience with topical calcitriol (1,25-dihydroxyvitamin D3) in psoriasis. British Journal of Dermatology 144: (suppl 58), 21-25.
Nevitt, G.J., Hutchinson, P.E. (1996)Psoriasis in the community. British Journal of Dermatology 135: 4, 533-537.
O’Neill, P., Kelly, P. (1996)Postal questionnaire study of disability in the community associated with psoriasis. British Medical Journal 313: 919-921.
Pardasani, A.G., Feldman, S.R., Clark, A.R. (2000)Treatment of psoriasis. American Family Physician 61: 3, 725-733.