Psoriasis is an inherited disorder of the skin, which causes red, scaling bumps and patches on the skin. It is a chronic disorder, which means that the symptoms come and go throughout a person's life.

What is going on in the body?


Psoriasis is an inherited disease that causes an increase in skin cells on the outer layer of the skin. In a healthy individual, skin cells mature and shed from the surface of the body about every 28 days. People with psoriasis shed skin cells every 3 to 4 days. The excess skin cells build up and form the skin lesions of psoriasis.

What are the signs and symptoms of psoriasis?

Following are the five major types of psoriasis, each with its own characteristic skin lesions:

  • erythrodermic psoriasis, which causes reddening and swelling of large areas of skin
  • guttate psoriasis, which causes small skin lesions that look like drops of fluid
  • inverse psoriasis, which causes smooth red lesions in the folds of the skin
  • plaque psoriasis, the most common type, which causes raised red skin lesions that develop silvery-white scales
  • pustular psoriasis, which forms blisters filled with thick white material

Other symptoms of psoriasis are as follows:

  • crumbling or abnormal fingernails and toenails
  • itching
  • thickening, cracking, and blistering of the palms or soles of the feet

The severity of symptoms may range from a mild cosmetic problem to a disfiguring, disabling condition.

What are the causes and risks of psoriasis?

The exact cause of psoriasis is unknown, but it is commonly believed that the body's immune system triggers the rapid growth and shedding of skin cells. Several genes have been linked to psoriasis, which tends to run in families. However, many people with psoriasis have no family history of the disease.

Certain factors seem to trigger plaque development in people with psoriasis. Suspected triggers include the following:

  • agents that damage the skin, including chemicals, electricity, and infectious agents such as bacteria
  • alcohol
  • bodywide infections, including HIV
  • excessive scratching
  • hormonal changes
  • injuries to the skin, including sunburn
  • seasonal changes in climate
  • smoking
  • some medicines, including beta-blockers, antimalarials, and NSAIDs
  • strep throat
  • stress

A person can develop psoriasis at any age. However, it most often develops in two age ranges. The first is between 16 and 22 years of age, and the second is between 57 and 60 years of age. It affects men and women equally and is seen in all races. However, psoriasis is more common in people of Western European and Scandinavian ancestry.


Prevention & Treatment of Psoriasis

What can be done to prevent psoriasis?

Psoriasis cannot be prevented, but it can be controlled. Certain triggers may be controlled or eliminated to help curb the outbreaks. Take these measures to prevent flare-ups of psoriasis.

  • Avoid sunburn by limiting sun exposure, following recommendations from your healthcare provider.
  • Limit the skin's exposure to water by taking short showers and baths and by limiting swimming.
  • Eliminate triggers such as alcohol and smoking.
  • Avoid rubbing or scratching the skin.
  • Avoid clothing or sports equipment that rubs the skin.
  • Use skin care products recommended by the healthcare provider to avoid dry skin.
  • Use stress-management techniques as needed.
  • Discuss medicines with your healthcare provider and avoid those that trigger flare-ups of psoriasis.
  • Seek prompt treatment of infections and other illnesses.

How is psoriasis diagnosed?

A healthcare professional can diagnose psoriasis by doing a medical history and complete physical examination. The characteristic skin lesions will show what type of psoriasis an individual has.


What are the long-term effects of the disease?

Psoriasis can have an emotional, as well as a physical, impact on people. Psoriatic arthritis, a form of joint inflammation that occurs in some people who have arthritis, can be painful and disabling.

What are the risks to others?

Psoriasis is not contagious and poses no risk to others.

What are the treatments for the disease?

An assessment of lifestyle, including stress levels and aggravating factors, should be made. Triggers should be reduced or eliminated.

Gentle removal of scales is important. Oils or coal tar preparations can be added to baths, and a soft brush can be used to scrub lesions carefully. Emollient creams, such as those containing alpha hydroxy acids or salicylic acid, may be used after bathing to soften thick scales. A regular skin routine is important, even when no flare-up of psoriasis is present.

Mild to moderate cases of psoriasis can also be treated with medicines that are applied to the skin, including:

  • anthralin
  • coal tar
  • medicines derived from vitamin D
  • retinoids, or vitamin A derivatives
  • steroid creams and ointments, which may be covered with a dressing to increase their effectiveness


Treating Moderate to Severe Cases of Psoriasis

Moderate to severe psoriasis may be treated with phototherapy, or exposure to light, that is carefully prescribed by the healthcare provider. Possible options include:

  • PUVA photochemotherapy, which uses a light-sensitizing medicine known as methoxsalen together with ultraviolet A light
  • sunlight
  • ultraviolet B irradiation along with one or more topical medicines

Severe psoriasis is often treated with the following oral medicines:


  • cyclosporine
  • methotrexate
  • retinoids, such as isotretinoin and acitretin

Isolated patches of psoriasis that are resistant to other therapy may be injected with triamcinolone acetonide.

What are the side effects of the treatments for psoriasis?

Side effects of steroid creams and ointments include thinning of the skin and stretch marks. Coal tar can make the person sensitive to ultraviolet light. Anthralin and vitamin-based products can irritate the skin.

Phototherapy increases a person's chance of developing skin cancer or premature aging of the skin. Retinoids can cause birth defects if taken by a pregnant woman. Methotrexate can damage the liver, while cyclosporine can damage the kidneys.

What happens after treatment for psoriasis?

Psoriasis should clear substantially with appropriate treatment, although this varies from person to person. Treatment of psoriasis is lifelong.

How is psoriasis monitored?

Any new or worsening symptoms should be reported to the healthcare provider.