A threshing floor in Santorini in Greece. Russian women using a hand powered winnowing machine in a barn. Note the board across the doorway to prevent grain from spilling out of the barn, this is the origin of the term threshold.
Psoriasis is not contagious. It is not something you can âcatchâ or that others can catch from you. Psoriasis lesions are not infectious and cannot be passed from person to person.It is okay to have contact with people who have psoriasis.t is not something you can âcatchâ or that others can catch from you. Psoriasis lesions are not infectious and cannot be passed from person to person. It is okay to have contact with people who have psoriasis.
They include: 1  Injury to the skin: Injury to the skin has been associated with plaque psoriasis. 2  Sunlight: Most people generally consider sunlight to be beneficial for their psoriasis. 3  Streptococcal infections: Some evidence suggests that streptococcal infections may cause a type of plaque psoriasis.