How does psoriasis develop?

Don't know: The cause of psoriasis is still unknown. Many theories, no final answer. Genetics have been suspected, but twins’ studies showed no clear conclusion. Alternation of immune system or autoimmune disorder has been favored. Recent popular regimens like biologics are based on such understanding and actually presenting very promising results. Infection has been a known cause of certain type of psoriasis.

Psoriasis: Typically it is an autoimmune disease that attacks the skin cells and the epidermis. http://www.aad.org/skin-conditions/dermatology-a-to-z/psoriasis#.uvdbzldwolr.