Our skin cells have a life cycle. During this cycle, skin cells grow deep in our skin, slowly rise to the surface and eventually die and fall off our skin. Normally, this process takes one month.
Psoriasis is a condition when this skin production speeds up, and occurs in just a few days. Due to which, skin cells don't get sufficient time to fall off. So they grow and accumulate rapidly on the surface of the skin. Subsequently, scales and red patches are formed, which are itchy and even painful sometimes.
First, your immune system. When your white blood cells, which are supposed to fight bacteria and infections, attack your skin cells by mistake, the skin production process speeds up. This can lead to Psoriasis.
Second, your genes or heredity. Some people are passed on certain genes that make them more susceptible to get Psoriasis. So, if you have any immediate family member who has or had the condition, there are considerable chances of you getting Psoriasis.
These are creams, gels or lotions that can be directly applied to the affected area if you have mild to moderate Psoriasis. Common examples of these medications are topical corticosteroids, topical retinoids, anthralin, Vitamin D analogues, salicylic acid and moisturisers.