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What is Psoriasis?
 Psoriasis is a relatively common skin disease affecting 1% to 2% of the population. The main feature of psoriasis is a red, scaly area or patch. The patches appear particularly on the knees, elbows and scalp and sometimes on other parts of the trunk, and legs. Psoriasis affects both sexes and all races. It can occur at any stage of life, although it starts most frequently in young adults.
Itching is usually only mild. Psoriasis only rarely affects general health apart from arthritis. A flare in a person’s psoriasis can, however, have a profound impact on an individual’s feelings of wellbeing and have a major impact on their way of life and daily activities. Once a person develops psoriasis it usually continues, although it may get better or worse over time and even seem to disappear for prolonged periods.
soriasis on the body
What Causes Psoriasis?
 Although no one single cause for psoriasis has been found, it is known that inherited factors are important.
In a person predisposed to get psoriasis, psoriasis can be brought out or made worse by emotional stress, scratching, rubbing, injury, certain medications, some infections and smoking.
It is currently thought that the main problem in psoriasis is an increased activity of the immune system in the skin, causing white immune cells (lymphocytes) to accumulate in the skin and produce a range of chemicals (such as tumour necrosis factor, interleukins, interferons and growth factors). These immune cells and the chemicals produced trigger changes in the skin which lead to an abnormally rapid rate of skin cell multiplication or turnover, which in turn causes skin affected by psoriasis to thicken, redden, shed an increased number of visible skin scales and contributes to sensations of skin irritation or itch.Pustular patches of psoriasis
What Parts of the Body are Involved?
 Any part of the skin can be involved including the knees, elbows, palms, soles, scalp and the genital area. The nails are frequently involved and may be hard to distinguish from a fungal infection. Sometimes it affects a person’s entire skin surface but fortunately this is rare. Many cases are very mild.
About 8% of people with psoriasis of the skin may also have involvement of the joints. Joint involvement can cause pain and swelling (arthritis). The most frequent form of arthritis involves one of the larger joints such as the knees, ankles or back. Other people may just have involvement of the finger joints adjacent to the nail, or occasionally the arthritis can be widespread.
What Kind of Treatments are Available?
There are many treatments available for people with psoriasis. Unfortunately, no one treatment helps everyone with psoriasis, and previously beneficial therapies may fail to settle a subsequent flare but then work again in the future. Treatment recommendations usually vary depending on the severity and location of psoriasis, its impact on a person’s quality or way of life and other existing medical conditions.
It may be necessary to rotate through different treatments at different times, or to combine treatments for faster clearance of psoriasis, particularly in those with more severe or widespread disease.
If your psoriasis is getting you down or interfering with your enjoyment of life, you should tell your general practitioner or dermatologist about your feelings and how your psoriasis is impacting on your everyday activities.
TOPICAL TREATMENTS
Several topical therapies are available without prescription. Over the counter products that can help those with psoriasis include: tar and oil baths, medicated shampoos and the regular use of a moisturiser. They may be all that is necessary in those with mild disease.
Cortisone, tar, anthralin (Dithranol) and vitamin D based (calcipotriol) creams and ointments remain the mainstay of treatment for most with psoriasis.
CORTISONE (STEROID) CREAMS
These are the commonest treatment prescribed for psoriasis and are helpful in reducing inflammation and irritation. The main problems are that the skin can become accustomed to the steroid over a period of time and, with prolonged use of strong cortisone creams, thinning of the skin can occur. The choice of steroid varies depending on the severity of the lesions and their location (e.g. scalp, face or skin folds). You should check with your doctor and pharmacist about how often and for how long the steroid cream prescribed for you can be used on the same area. Also, by attending your doctor’s recommended follow-up appointments, your doctor can assess and tailor your ongoing management plan to minimise risk of both of these problems.
TAR
Tar has been used for over one hundred years and is usually effective in treating psoriasis. Unfortunately, it can be smelly and may stain clothing. Tars are made from the distillation of coal and wood. They can be used as creams and shampoos. Application is usually at night to minimise odour during the day. Tars may also make you more sensitive to the sun.
CALCIPOTRIOL
Calcipotriol is a medication related to vitamin D and can be effective in treating psoriasis. It is usually well tolerated. It can cause irritation, particularly when used on sensitive skin areas such as the face or groin. If it is making your psoriasis redder, angrier or more itchy and uncomfortable, you should stop its use and see your doctor. If too much is used (a greater amount than recommended, particularly in children), there is the possibility of increasing the level of calcium in the blood. The calcium level in the blood may be checked periodically if large quantities are required.
ANTHRALIN (DITHRANOL)
Anthralin is extracted from tree bark. It can be used in a thick ointment that is left on overnight, sometimes under dressings, or more commonly applied at higher concentrations for 10-15 minutes before removal.
Anthralin is usually very effective in treating psoriasis. The main potential problems with anthralin are irritation of the skin, temporary skin discolouration and permanent staining of fabric.
LIGHT TREATMENT (PHOTOTHERAPY)
People with psoriasis often take advantage of natural sunlight’s beneficial effects. Sunlight is made up of visible light and a variety of invisible rays. These invisible rays include ultraviolet and infrared or heat rays. The ultraviolet wavelengths of sunlight have been shown to be most effective in improving psoriasis.
Light treatment is effective in most people with psoriasis. Light is mainly used for treating people with widespread psoriasis. There are three main types of ultraviolet (UV) light treatment used in Australia to treat psoriasis: Narrow Band UVB, Broad Band UVB and PUVA. A measured dose of the appropriate wavelength of light is delivered by a number of specially designed fluorescent tubes that line the walls of a special light cabinet (for treating the whole body) or organised in panels designed for treating just the hands and/or feet.
Unfortunately, as is widely known, ultraviolet light can cause skin cancer. However, when creams have failed, ultraviolet light is usually extremely effective, but may not work for everyone with psoriasis. In order to minimise the dangers, special treatment methods have been developed.
UVA is the “weakest” form of ultraviolet light and this is combined with the administration of psoralens, natural substances which come from plants like celery. The combination is called PUVA which is short for psoralens and UVA. This combination, however, has the highest risk of side effects.
Another method is the use of Narrow Band UVB. This can be likened to tuning a radio to a single band (around 311nm). The wavelength of light determines the quality or effects of different parts of the light spectrum such as warmth, colour and ability to burn the skin. This narrowband incorporates the sun’s most beneficial rays for treating psoriasis and leads to faster and more prolonged benefits compared to broadband phototherapy and natural sunlight. NB-UVB does not contain ultraviolet’s shorter, most sunburning and potentially dangerous wavelengths.
Because it is a powerful and potentially dangerous treatment, ultraviolet light should only be administered by practitioners skilled in its use. Disadvantages include the need for several treatments a week over several weeks, and long term damage to the skin, including a possible increased risk of skin cancers, and increased skin (photo)ageing.
Light treatment is available at some hospitals, Skin and Cancer Foundations and at some dermatologists’ offices.
ORAL (INTERNAL) TREATMENTS
A number of tablet treatments are available, and these have proven very effective in most people living with psoriasis but, like all medications and therapies, can cause potentially serious side effects. These treatments include methotrexate, acitretin and cyclosporin. Careful choice of therapy and skilled monitoring reduce the potential risks of these therapies, which are generally very effective in controlling even severe cases of psoriasis. Methotrexate is taken once a week and works largely via modulating the immune system. Acitretin is a derivative of vitamin A. Acitretin helps program the skin cells back to normal and also has effects on the immune system. Cyclosporin, like methotrexate, works via its effects on the immune system.
NEW INTERNAL TREATMENTS
A number of new biological agents have been developed or are under development for treating psoriasis. These interfere with the immune mechanisms that lead to psoriasis, helping to rebalance or normalise the skin immune system. They work by targeting the abnormal immune cells or their chemical products involved in causing lesions of psoriasis.
At present, only a limited number of biological agents have been shown to be effective in treating psoriasis. These all need to be given by injection (into a vein or into muscle). They are currently used for more severe and recalcitrant cases, and are expensive.
NATURAL THERAPIES AND LIFESTYLE CHANGES
People who smoke have a higher risk of developing psoriasis than non-smokers. Giving up smoking after the onset of psoriasis will not, unfortunately, lead to the clearance of psoriasis.
People with psoriasis often take advantage of natural sunlight’s beneficial effects. Light therapy using a special fluorescent light bulb is, however, safer and more effective.
Any cream with moisturising properties can be beneficial in improving psoriasis and this is the probable basis for a number of non-prescription “miracle” treatments.
Diet has not been shown to be an important factor in controlling or treating psoriasis. However, obesity leading to large folds of skin can make psoriasis in these folds difficult to manage. Excessive alcohol consumption may worsen psoriasis.
Wearing light rather than dark coloured clothes can make shed skin flakes less obvious.
Vitamin A and vitamin D are beneficial in psoriasis, but the high doses required to help those with psoriasis are potentially toxic or dangerous. Thus, safer, less toxic vitamin analogues have been developed (calcipotriol & acetretin) which require a prescription from your doctor. Check with your doctor before taking a specific high dose vitamin A or vitamin D supplement.
Psychological distress can have profound effects on the immune system. Such distress is reported as a trigger factor by around two thirds of people with psoriasis, and the most stressed do least well in therapy. A psychologist may be able to teach you better ways of coping with the problem.
IN SUMMARY …
With appropriate treatment, psoriasis can be well controlled for the vast majority of sufferers and a normal lifestyle enjoyed. Unfortunately, not everyone responds to all therapies and, in some people, particularly those with more severe psoriasis, combination therapy may be required.
At this stage it is not possible to cure psoriasis.
WHAT FURTHER INFORMATION IS AVAILABLE ABOUT PSORIASIS
If you think you have psoriasis, it is important to have the diagnosis confirmed by a medical practitioner. If you know you have psoriasis, then your medical practitioner and, if necessary, your dermatologist can provide further information about its treatment. There is a very active self help group, The Psoriasis Association, in most parts of Australia, which is a source of practical information provided by fellow sufferers. It is important to realise that the extent of involvement with psoriasis varies greatly from one individual to the next and the majority of people do not have more than nuisance problems with it over a lifetime.
The Australian Psoriasis Support Groups can be reached at these links:
AUSTRALIA
USA
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