Genetics of Psoriasis
As yet, we do not know which genes are responsible for psoriasis. Though many candidate genes have been identified, none explain all causes of psoriasis. It is very likely that more than one gene is necessary to get psoriasis. In fact, psoriasis sometimes behaves as if each person had a "different" disease with huge variations in types and severity of psoriasis suggesting multiple genetic programs. The idea that multiple genes are involved is supported by the very different response to treatment seen between patients. One person's psoriasis may respond well to many different therapies while another person's psoriasis - appearing identical to the first, responds poorly to almost everything.
Psoriasis Triggers
Triggers are as important as genes in the development of psoriasis. Genes are from our biological parents - we cannot choose our genes. Similarly, psoriasis triggers are part of life and cannot be avoided. Accidental injuries, scrapes, cuts, burns, stitches, infection which may even include the common cold - can trigger psoriasis in some people. No one knows for sure but it is very possible that the psoriasis trigger is different for each person depending upon their genes.