The exact causes of psoriasis are not clearly known. Doctors and other researchers believe that, in some, the causes of psoriasis may stem from problems with the immune system or environmental factors, while others may have a genetic predisposition to its development. While psoriasis causes are not entirely clear, there is evidence pointing to very specific causes of psoriasis flareups in certain individuals.
While studying the causes of psoriasis, researchers have discovered that it is often due to a malfunctioning immune system. More specifically, biopsies of skin cells taken from patients with this condition have shown an abnormal influx of white blood cells, which cause skin overgrowth. As the primary symptoms of psoriasis, this excess skin is scaly in appearance and tends to bleed more easily than unaffected skin.
Research has also discovered that individuals living in cold climates are more prone to developing psoriasis than individuals living in warmer climates. Cold climates may especially contribute to causes of psoriasis in African Americans and Caucasians more so than other ethnic groups. Also, this skin condition does not appear to be very prevalent in these same groups living in warmer climates, nor is it often found to affect individuals of Native American ancestry.
While not everyone with this condition has a near relative who also suffers from psoriasis, it does have a tendency to run in families. This evidence strongly suggests that one of the causes of psoriasis is heredity. In the United States, as many as 35% of all who suffer with this disorder also have a family member with the disease.
The causes of psoriasis flareups may vary from individual to individual. In some people, psoriasis may be triggered by climate changes, stress, sunburn or other skin injuries. For others, it may be triggered by an infection. A specific type of psoriasis, known as guttate psoriasis, is particularly triggered by infections such as strep throat, upper respiratory infections, or other viral and bacteria infections. Overconsumption of alcohol appears to also trigger this distinct subtype.
Although research does not have a clearly defined answer for the causes of psoriasis, it is clear that the condition is not contagious. Most people with the condition develop it naturally between their teen years and their mid-30s with roughly 40% of individuals in the United States developing symptoms under the age of 20 years old. While it is also not a gender-specific condition, research suggests that men develop psoriasis more often than women do.