Causes of Psoriasis

Psoriasis is a chronic skin disease, characterized by well-defined red patches on the skin that appear to be covered by a silvery flaky scale. It is estimated that psoriasis afflicts about three percent of the US population. Psoriasis comes in several variations but the most common form is chronic plaque psoriasis.

The exact cause of psoriasis is not well known. However, researchers believe that a combination of several factors contribute to the development of the disease. While their researches continue to find the cause – and cure – for the disease, researchers have at least isolated several factors that trigger flare-ups of episodes of psoriasis.

The scaling and inflammation of psoriasis happens when cells in the outer layer of skin reproduce up to 10 times faster than usual and collect on the skin’s surface. In normal skin cells, cells develop in the lower layers, and as the upper layer of skin die and flake off; the new skin rises to the surface to replace the dead cells. A person afflicted with psoriasis will have patches of skin go through this cycle at an accelerated rate.

The result is raised patches of red or purple skin covered with silvery scales. Psoriasis will typically appear on the elbows and scalp, but can also occur on the palms and soles of the feet as well as the torso. In mild cases, the silvery scales will cover only small area of the body. In more severe cases, the silvery scales occur over large areas all over the body.

Researchers have been able to identified nine gene mutations that are involved in causing psoriasis. One of these mutations is on chromosome number six and appears to be a major factor that leads to the development of the disease. The nine mutations appear to affect the T-helper cells, which make up part of the body’s immune system.

These gene mutations also affect the white blood cells, which produce antibodies to protect the body against foreign invaders and infections. Psoriasis appears to cause these white blood cells to become overactive.

These T-cells attacked the skin cells and set off a chain of events that triggers the skin cells to multiply so fast that they stack up on the surface of the skin. The normal life cycle of healthy skin cells is about 30 days; but skin cells affected by plaque psoriasis go through the entire process in only three to six days.

Not everyone who has these gene mutations will get psoriasis and not everyone who have psoriasis have these gene mutations. Researchers have also identified environmental factors that trigger psoriasis in people.

Even a common and minor injury to the skin can cause the formation of psoriasis. The symptoms don’t appear right away. It could take anywhere between two and six weeks or the first sign of psoriasis to appear after the initial injury and that injury can be as mild as a scratch or even the friction created by clothing rubbing against the skin. Some individuals can also develop psoriasis after a sunburn, viral rash or rash from a drug reaction.

Other psoriasis triggers can include emotional stress or streptococcal infection. As many as 80% of people who have psoriasis flare-ups reported emotional traumatic events either due to the beginning of a new job or due to the death of a loved person prior to the flare-ups. Researchers believe that these external stress factors trigger the onset of psoriasis because they negatively impact the immune system of the person.

Certain medications, such as blood pressure meds and beta-blockers as well as anti-malarial medications can aggravate psoriasis and causes flare-ups. Weather condition is another strong external trigger. Individuals who are exposed to cold and dry weather will be more prone to psoriasis flare-ups or aggregation of the condition, while people in hot, damp or sunny weather are likely to see a decrease of psoriasis flare-ups and improvements of their symptoms.

The most common infection that will trigger a psoriasis flare-up is streptococcal. This bacterium is responsible for tonsillitis, sinusitis or strep throat. The human immunodeficiency virus (HIV) is also associated with the development of psoriasis because of the effect it has on an individuals immune system.

Some people may experience psoriasis flare-ups when their body have low levels of calcium, or have if they do not have enough exposure to the sun, which is required by the body to produce vitamin D. While the body is able to produce or manufacture all the vitamin D it needs with adequate exposed to the sun. But researchers have been able to develop vitamin D supplements that have been shown to be effective in treating psoriasis.

Besides blood pressure, beta-blockers and anti-malarial medications, other drugs such as ACE inhibitors, lithium, and corticosteroids are known to either worsen psoriasis conditions or induce flare-ups. While corticosteroids are used to treat psoriasis with great effect, abruptly stopping or reducing the use of the drug can cause a large flare up.

Researchers continue to search for a definitive cause for psoriasis with the hope that once the cause is identified, more effective treatments will be developed, as well as developing preventative measures for those who are prone to developing psoriasis.