Psoriasis is an immune mediated disorder affecting more than 7.5 million adults (3% of the adult population) of US.
Psoriasis occurs due to the dysfunction of immune system leading to the inflammation such as scales or raised plaques on the body. The mechanism of the disease involves the speedy growth of skin cells due to an overactive immune system. Normally, it takes a month for the cell to grow and then shed while in people with psoriasis this happens in 3 to 4 days.
Psoriasis is characterized by the formation of scales or plaques on different parts of your body including scalp, elbows or knees. People with psoriasis may feel itching on the skin or burning or stinging feeling.
Not only skin but other tissues or organs of the body may also be affected by psoriasis. Some people may also be affected be psoriatic arthritis in which joints become painful, swollen, and stiff.
Symptoms of this disease often appear between the ages of 15 to 25, however they may appear at any age.[i]
Types of Psoriasis
The disease has been classified into five categories which are as follows:
The most common type of the disease is plaque psoriasis affecting about 80% people. Plaque psoriasis is characterized by formation of red and inflammation patches often having white or silver scales over the skin. The location of this plaque is the scalp, knees and elbows.
In most children, psoriasis of this type occurs. Guttate psoriasis is distinguished by occurrence of small pink colored spots which may in rare cases be raised or thick on arms, legs or the torso of a person.
Adults usually get pustular psoriasis which is characterized by formation of pus filled white colored blisters and inflammation and redness on broad areas of skin. Typically, it is localized to the hands or feet of most adults.
In Inverse psoriasis, bright red, shiny, and inflamed skin is formed. Inverse psoriasis is usually located under the armpits, breasts, groin region, or around genital skinfolds.
The most severe and rare type is the Erythrodermic psoriasis. In this type of psoriasis the skin looks sunburned and it covers large areas at once. The scales or patches may shed in sheets. Some people with erythrodermic psoriasis may also have fever or illness. It can also be life-threatening.
Symptoms of Psoriasis
The symptoms of this disease may differ from person to person depending on the type and areas of psoriasis. Most common symptoms of psoriasis include:
Raised and red skin
Inflammation on skin having red, brown or purple color
Whitish to silver colored scales over the red patches
Grayish scales over brown or purple patches
Cracking of dry skin and bleeding
Patches that cause soreness
Itching or burning around the patches
Thick and pitted nails
Painful and swollen joints in case of psoriatic arthritis
However not all individuals will experience similar symptoms. Some of the people with psoriasis may experience symptoms that are entirely different especially if they have a less common type of psoriasis. Also the symptoms of psoriasis occur in cycles such as severe symptoms may occur for a week and then clear up or even disappear completely. Furthermore the symptoms may worsen again with the flare up of disease and may remain for a few day or weeks.
Cause of psoriasis
Although the exact cause or pathophysiology of the disease in unclear but decades of research have given a general idea of how psoriasis may be caused. Typically two key factors have been found to trigger this disease; these include the one the immune system and second the genetics of a person.
As already discussed psoriasis is the result of an autoimmune condition in which the body of a person attacks itself and damages its own cells. The white cells of blood called as T cells attack the cells of skin mistakenly. In a normal person without the disease these T cells are responsible for attacking and destroying the bacteria and infections that attack the body. As the T cells start attacking body’s own skin cells overproduction of skin cells occurs to replace the damaged skin cells. The new skin cells are pushed up to the surface of the skin thus piling up and causing formation of dry patches and scales.
Psoriasis may also develop due to genetic factors in some people. You may inherit genes from an immediate family member who has had psoriasis thus making you at risk of developing psoriasis as well. However a low percentage of population (2 to 3%) has been found to be affected by psoriasis due to genetic inheritance.
Psoriasis triggers or risk factors
Some of the risk factors that may increase the chances of you getting psoriasis include:
Stress – reducing and managing your stress may reduce your chances of getting flare-ups of psoriasis.
Alcohol – excessive use of alcohol may cause more frequent outbreaks of psoriasis.
Injury- accidental cuts or scrapes can also trigger flare-up in some people.
Other factors – vaccines and sunburns may also trigger a new psoriasis outbreak.
Treatment of psoriasis
Different treatment regimens for psoriasis include:
In case of mild to moderate psoriasis the doctor may prescribe some creams and ointments to be applied directly to the affected skin. These include moisturizers, anthralin, salicylic acid, vit D analogues, topical retinoids and corticosteroids.
People who do not respond to topical treatment or who may have moderate to severe psoriasis are prescribed with oral or injectable medications which include retinoids, biologics, cyclosporine and methotrexate.
Another treatment for psoriasis is the treatment with natural or ultraviolet light. Natural light from sun kills the overreactive cells that attack the healthy cells of skin and cause them to overgrow. Ultraviolet light both UVA and UVB has proven to be helpful in decreasing the symptoms psoriasis.
People with moderate or severe psoriasis are usually given a combination treatment with topical, oral and light therapy. [ii]