What Causes Palmoplantar Psoriasis?

Immune System

Palmoplantar psoriasis is one of the most common forms of psoriasis. Psoriasis is predominantly an autoimmune disease. Normally the immune system is activated by viruses, bacteria and other infections. However, in the case of psoriasis, the immune system becomes abnormally activated to recognize the skin tissue as an infection. As a result, the white blood cells of the immune system release chemicals that cause inflammation, which leads to skin damage and the reddening and silvery scales that mark psoriasis. This can be especially difficult in the case of palmoplantar psoriasis because the skin on the palms and the bottom of the feet is very thick and leads to bothersome itching.

Genetic Factors

Four different genes have been linked to plamoplantar psoriasis. These genes are involved in the human leukocyte antigen system. Leukocyte is the formal term for white blood cells, and antigens are small chemicals (generally bits of bacteria or viruses) that activate the immune system. Genetic mutations that affect the leukocyte antigen system can lead to autoimmune diseases such as psoriasis. One gene, HLA-CW6, causes people not only to develop psoriasis but to develop it earlier in life.

Psoriasis Triggers

Palmoplantar psoriasis symptoms can come and go and are triggered by conditions that activate the immune system. Cold, dry weather, for example, can cause a flare-up of psoriasis. Stress and other emotional issues, such as unexpressed anger, have also been found to cause symptoms. Infection with the bacteria streptococcus (responsible for strep throat and tonsilitis) can cause a flare-up of psoriasis. Finally, some medications, including ACE inhibitors, lithium, beta-blockers and progesterone can either make psoriasis worse or lead to a flare-up.