Common Causes of Psoriasis
Doctors are not certain what causes psoriasis, but they do know how it might develop. The outer layer of our skin is constantly making new cells and shedding old ones. In psoriasis, the skin cells don't shed properly, but accumulate and remain on the outer layer of skin, forming scales. A genetic cause is suspected. Most doctors also believe that psoriasis may be one of the many diseases, in which the body has an immune reaction against itself.
There are many factors that may not directly cause psoriasis, but can aggravate or "trigger" an attack of symptoms in someone who is affected. The following factors can increase your risk of or may trigger psoriasis:
Stress: "Nerves" do not cause psoriasis and rarely trigger the first attack, but as many as 80% of those having flare-ups report a recent emotional trauma, such as a new job or the death of a loved one. Many doctors believe such external stressors serve as triggers for an inherited defect in skin cell production.
Family history: Often, a person with psoriasis has a parent or grandparent who also has the condition. Researchers estimate that a person with one affected parent has about a 10% chance of also having psoriasis. Having two parents with psoriasis increases the chances to about 30%.
Hormonal changes: There appears to be a relationship between hormonal changes and the onset and severity of psoriasis symptoms. At puberty, in males and females, psoriasis may develop or become more severe. As women reach menopause, they may experience an increase in symptom severity. During pregnancy, psoriasis lesions undergo improvement, but they may reappear after the child is born.
Other Causes of Psoriasis
Infections: A throat infection with the Streptococcus bacteria often triggers an attack of psoriasis in children. In addition, an adult with chronic psoriasis may develop a flare-up after a streptococcal throat infection. This reaction develops about two weeks after the infection, suggesting that the Streptococcus bacteria trigger an immune response in predisposed individuals.
Injury to the Skin: Psoriasis patches may form at skin injury sites. This is referred to as the Koebner Phenomenon.
Certain medications: Some medications, including those used to treat people with high blood pressure or heart disease (called beta-blockers) or those used to treat bipolar disorder (for example, lithium carbonate) have been found to worsen psoriasis symptoms. Medications used to prevent or treat malaria may also trigger psoriasis.
Climate: Cold, dry winter weather tends to trigger a flare-up of psoriasis symptoms. In contrast, sunlight and humid, sunny climates are, as a rule, helpful - particularly in mild cases. However, hot, humid environments may make severe cases of psoriasis worse.
Wearing tight clothes, hats, shoes and jewelry: Tight-fitting clothing and accessories may irritate your skin and cause psoriasis symptoms to worsen.
Alcohol and smoking: Alcohol may be a risk factor for young and middle-aged men, and severe psoriasis is sometimes seen in people who drink excessive alcohol. Smoking may also act as a trigger for psoriasis.
Diet and obesity: Doctors are unsure of the role that a person's diet plays in psoriasis, but they suspect that eating habits have only a small role in this skin disorder. Keep in mind that a well-balanced diet is part of a healthy lifestyle in people with or without psoriasis.