Psoriasis is the chronic recurring skin condition that causes raised, red patches on the skin and a coating of silver scales.
Psoriasis affects almost 20 million people globally yet public awareness of the condition is remarkably low. What’s more a 2005 study by Datamonitor revealed that as many as 45% of sufferers, or 8 million people, are undiagnosed.
It is expected that the undiagnosed sufferers are predominantly suffering from a mild form of psoriasis. These people are either self medicating, using non-prescription medication or their condition is going totally untreated.
Datamonitor healthcare analyst Clare Churchill says “Datamonitor estimates there are 18 million psoriasis sufferers in the 7 major pharmaceutical markets with up to 16% of those developing psoriasic arthritis.”
Psoriasis prevalence is low in Japan and East Asia in general, and extremely low to non-existent in ethnic groups native to North and South America.
What is Psoriasis?
Psoriasis is the result of an overproduction of skin cells. The exact reason for this is unknown however, there is usually a genetic predisposition to being affected. In most cases a close family member will also suffer from the condition.
Research has shown that white blood cells known as T Lymphocytes or T cells are activated triggering the immune system to respond. This ultimately results in a trigger that causes an overproduction of skin cells and so the psoriasis.
T cells are lymphocytes that complete their maturation in the thymus, hence the name T lymphocytes. They have various roles in the immune system, including the identification of specific foreign antigens in the body and the activation and deactivation of other immune cells.
The reason for the instigation of an immune response in psoriasis is not clear. For some reason the T Cells mistakenly target the cells of the person’s own body as foreign and launch an attack.
The difference between normal skin and psoriasis skin
The normal skin cell takes about 28 days to develop, mature and shed. The psoriasis cell will complete this process in between 3-6 days. The result is an excess amount of cells being formed which do not provide the skin with its natural protective layers. These excess cells create thick, red, white or scaly patches on the skin’s surface. Extra cells will build up on the skin forming plaques.
The most common sites to be affected by psoriasis are the knees, elbows, scalp, hands, feet and lower back. Psoriasis is very uncomfortable and may cause severe itching.
Where to now?
Public awareness of psoriasis is remarkably low despite efforts to increase peoples’ awareness. Clare Churchill believes extensive marketing campaigns for new biologic treatments entering the market will improve the awareness of psoriasis. And along with increased awareness will come increased rates of diagnosis and treatment.
“In fact the American Academy of Dermatology launched a public awareness campaign in early 2005 in the US. This campaign coupled with the increased awareness brought about by treatment marketing campaigns, will no doubt help to tackle the ongoing problem of low diagnosis rates,” Churchill says.
Treating Psoriasis
Despite 1-3% of the world population suffering from psoriasis there is still no cure for the condition. Current treatments aim at treating the symptoms or prolonging the outbreaks. Treatment choices are determined by the type of psoriasis, the severity of the condition, the size of the area involved and the patient’s response to initial treatment.
Churchill says treatments are usually carried out in steps. “In step 1, medicines are applied to the skin (topical treatment). Step 2, uses light treatments (phototherapy) and Step 3, includes taking systemic medicines that treat the whole immune system.
“Variations from this approach include combinations of therapy, which according to physician research are used in increasingly severe patients, with 45% of the most severe patients using a combination of pharmaceuticals and non-pharmacological treatments like phototherapy.”
A ‘trial and error’ approach is often taken by doctors because not all treatments will have the same effect on each patient. There is also the risk that over time the affected skin will become resistant to a certain treatment. This results in a doctor often having to switch treatments.
Psoriasis is a non-life threatening condition so doctors are often less willing to take risks with their treatment options than they would be in a life threatening condition. Systemic treatments are generally reserved for severe cases of psoriasis, as are the new form of biologic treatments.
Where to next?
Research into new treatments for psoriasis is ongoing. A new range of treatments has recently become available known as Biologics.
Biologic medications have been around for more than 100 years in the form of vaccines and insulin however Biologics specifically designed to target and treat psoriasis and psoriatic arthritis have only become available in recent years.
Biologic medications are made from living human or animal proteins – unlike most medicines, which are produced by combining chemicals.
Like most psoriasis treatments, Biologics target the immune system. The difference is the likes of ultraviolet light treatment, methotrexate and cyclosporine act broadly on the immune system and have potentially serious side effects. Biologics are more targeted and are potentially safer.
How do Biologics work?
Biologics act on the T cell in the immune system preventing it from becoming activated or migrating to the skin. The roll of the T cell is to identify bacteria and viruses and co-ordinate the immune system to respond to and fight the foreign invaders.
In psoriasis some T cells become activated for unknown reasons. Once activated they migrate to the skin and act as if they are fighting an infection or healing a wound. This in turn stimulates an increase in the production of skin cells causing a pile up of cells at the site. And so the psoriasis lesion forms.
Biologics prevent the initial migration of the cell and therefore block psoriasis early in its development in the immune system.
Biologics are most likely to be used to treat more severe cases of psoriasis. They are given by injection usually in instances when conventional treatments have not been effective.
As these medications are still relatively new, long-term safety, especially of the newer biologics is still being reviewed. However short-term side effects appear to be considerably reduced with the main concern being an allergic type reaction to the injection. There is also not the same risk of liver or kidney damage or bone marrow suppression as with conventional treatments.