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.
Psoriasis typically starts or worsens because of a trigger that you may be able to identify and avoid. Factors that may trigger psoriasis include: 1  Infections, such as strep throat or skin infections. 2  Injury to the skin, such as a cut or scrape, bug bite, or a severe sunburn. 3  Stress. 4  Cold weather. 5  Smoking. 6  Heavy alcohol consumption.