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Practice nursing basics: psoriasis

James Britton
MB BS BMedSci(Hons) MRCP(UK)
Specialist Registrar
Dermatology Department
Leeds General Infirmary
Company Director

For the healthcare professional, knowledge and understanding of psoriasis are crucial when choosing an appropriate therapy. Good skills and training are also vital. However, the person who requires the most information about the condition is the patient, as he or she will be responsible for the mainstay of treatment, the application of topical therapies, and will have to live with the condition on a daily basis.

There are widely held misunderstandings and prejudices about skin conditions, particularly the causes of skin conditions. Helping the patient with psoriasis to fully understand their condition and providing them with information can relieve some of their stress and anxiety.

Making the diagnosis
There are two main types of psoriasis - plaque psoriasis and guttate psoriasis. Psoriasis adopts different patterns on the skin, depending where it occurs. For example, psoriasis found in the groin or armpits will appear different from psoriasis on the arms or trunk.

Plaque psoriasis
The following are features of plaque psoriasis:

  • Red scaly plaques of skin on the knees and elbows (see Figures 1 and 2).
  • Red scaly plaques behind the ears and on the scalp.
  • Pitting, splitting and thickening of the nails - ­onycholysis and onychodystrophy (see Figure 3).
  • Red scaly plaques of skin on the lower back.




The scale associated with psoriasis has been described as a "silvery scale", and the redness of the plaques has been described as "salmon pink". The raised red scaly areas of skin are known as "psoriatic plaques" (see Figures 1 and 2).

Guttate psoriasis
The following are features of guttate psoriasis:

  • Small red plaques over the trunk and limbs (see Figure 4).
  • Quick onset over a few days, often after a sore throat or tonsillitis.


Plaque and guttate psoriasis are the most common forms and can overlap in appearance.

Other presentations
There are other less common patterns of psoriasis:

  • Pustular psoriasis - widespread small pustules on the skin.
  • Palmoplantar psoriasis - affecting the palms of the hands and soles of the feet.
  • Erythrodermic psoriasis - a serious flare-up of psoriasis that can require hospital treatment as an inpatient.
  • Psoriasis can also occur in scratches and cuts, known as the Koebner phenomenon.

Another complication of psoriasis is when joints are affected. This causes pain and swelling and is known as "psoriatic arthritis". Not everyone with psoriasis will develop psoriatic arthritis, which in itself can have different patterns:

  • Single large joints - knee, hip and wrist.
  • Joints of the fingers.
  • Affecting the spine.

Understanding the causes
The exact cause of psoriasis is not known, but once the diagnosis is made it is important to stress that the condition cannot be passed on to others. A great deal of prejudice that a patient with psoriasis experiences stems from the ignorance of others.

Unwanted inflammation and increased turnover of skin cells cause the redness and scale of the skin plaques. Normal skin cells are replaced every 21 days, but this is dramatically reduced in psoriasis, producing the characteristic buildup of scale on the plaques.

There is a genetic link with psoriasis as it can run in families. However, the genes involved are complex, and a combination of genes is needed, so not all family members will develop the condition. Having the genes that cause psoriasis is not enough for the condition to develop. An "environmental trigger" is also needed to start the process of inflammation and increased skin turnover. When guttate psoriasis develops after a sore throat the bacteria that causes the inflammation in the throat, streptococcus, can be regarded as the trigger. Other triggers are not known.(2)

As the causes of psoriasis are not fully understood, the patient must be made aware that there is no simple cure. This can be very disappointing but is essential so as not to give false hope.

Understanding how psoriasis affects the sufferer
People with psoriasis cope in different ways. The symptom of itching, which leads to scratching, bleeding and pain, can be very uncomfortable and distressing. These symptoms can be relentless and after a long period of time can lead to depression.

The prejudice that a patient may experience can also be quite demoralising. The appearance of red scaly skin draws unwanted attention from others and may be a reason for the patient with psoriasis to avoid displaying their skin by wearing long sleeves and trousers. Swimming is often avoided.

The treatments are also messy and time-consuming to apply, and the motivation to use them can wane.

There is no doubt that having psoriasis causes stress, but the link between stress and psoriasis is not as clear. Some patients indicate that a stressful event occurred around the time of the first episode, and some note that stress can cause a psoriasis flare-up, although this is very much down to the individual.

Emotional support and understanding are vital and cannot be stressed enough, as having to suffer the symptoms of psoriasis can drive a person to attempt to take their own life.

The progress and treatment of psoriasis
The occurrence of psoriasis varies between individuals. Some patients may have had their first episode during childhood, but then not again until adulthood. For others the psoriasis may have continued throughout their childhood, teenage years and early adult life. Others may not have an episode until middle age or even later.

It is important that the patient knows that the face is often the least affected area of the body. This may provide reassurance as the skin on the rest of the body can be covered up. It is also important for the patient to know that the psoriasis is not always so extensive as to cover the whole body, and that there are many treatments available to keep psoriasis under control and maybe even clear it.

How each person's psoriasis behaves and how they are coping with it governs the treatment choices. Treatments can be divided into the following categories:

  • Topical - treatments applied to the skin.
  • Physical - light treatment.
  • Systemic - treatments taken by mouth.

Topical treatment is the mainstay of treatment for psoriasis, and the use of moisturisers in particular is crucial to reduce itchiness. The use of topical therapies is time-consuming and can easily be forgotten, especially when it has to fit into a busy lifestyle. Care must be taken to discuss and decide with the patient a regular time during the day when treatment can be applied, as application may take up to 30 minutes.

Apart from moisturisers, active treatments such as topical steroids, tar preparations and vitamin D analogues can also be used at home. Other treatments such as dithranol need special care as they can irritate and stain the normal skin and anything that they come into contact with.

Most dermatology centres offer "bathroom treatment", where specialist nurses apply the treatment for patients up to three times per week, usually involving bathing in bath oil, hence the name "bathroom ­treatment".

Physical ultraviolet light treatment is available only at specialist dermatology units as it needs careful monitoring. It is used only when the patient has not responded to topical therapy alone, or if the patient has guttate psoriasis that responds very well to UV light. UV light can be very successful and can clear psoriasis in an eight-week course. Care is needed as UV light in the short term can cause burning, and in the long term too much exposure can increase the risk of skin cancers.

Systemic treatment is reserved for people whose psoriasis is difficult to control on all other treatments. It includes the use of ciclosporin, methotrexate and vitamin A derivatives. Systemic treatment is usually given in specialist dermatology centres. Specialist nurse-led clinics are held to monitor patients' blood tests and treatment doses carefully, as the side-effects need close attention.

Throughout any treatment regimen the careful use of moisturisers and other topical treatments should be meticulously maintained.

The long-term treatment of psoriasis is governed by how the psoriasis responds to the treatment and how the patient is coping. In some situations the person may need both mental and physical support, and hospital admission may be appropriate.

Psoriasis affects each individual differently. It requires careful communication to understand how the patient is coping with the symptoms, and to tailor the therapy for maximum success.



  1. Rea JN, Newhouse ML, Halil T. Skin disease in Lambeth. Br J Prevent Soc Med 1976;30:107-14.
  2. Champion RH, Burton JL, Burns DA, Breathnach SM, editors. Rook Wilkinson Ebling textbook of dermatology. 6th ed. Oxford: Blackwell Science; 1998.

Psoriasis ­information and treatment

Information about phototherapy

Information about topical steroids

Information about vitamin D analogues