Causes of Psoriasis

Psoriasis is driven by the immune system, especially involving a type of white blood cell called a T cell. Normally, T cells help protect the body against infection and disease. T cells help create scabs over wounds. In the case of psoriasis, T cells are put into action by mistake and become so active that they trigger other immune responses, which lead to inflammation and to rapid turnover of skin cells.

Most recently, the natural or innate immune system has been found to be highly implicated. Non-specific natural responses of the skin immune system, and virtually every subsystem of that, are activated in psoriasis. Epidermal cells come out on the skin, forming itchy patches or plaques. The first outbreak of psoriasis is sometimes triggered by emotional or mental stress or physical skin injury, but heredity could be major factor as well. In about one-third of the cases, there is a family history of psoriasis. Researchers have studied a large number of families affected by psoriasis and identified genes linked to the disease. (Genes govern every bodily function and determine the inherited traits passed from parent to child.) People with psoriasis may notice that there are times when their skin worsens, then improves. Conditions that may cause flare-ups include infections, stress, and changes in climate that dry the skin. Also, certain medicines, including Lithium salt and beta blockers, which are prescribed for high blood pressure, may trigger an outbreak or worsen the disease. Other autoimmune diseases such as HIV/AIDS may significantly worsen the symptoms of psoriasis. Alcohol consumption and obesity may also worsen the condition.