Whether you get plaque psoriasis depends on your genes and your health history:
Psoriasis isn't contagious. It can't be spread by touch or other close contact.
- Heredity: Psoriasis seems to run in families. About 10% of people are born with genes that make them likely to get psoriasis. But only about 3% of people get the disease.
- Triggers: Something has to happen to start your immune system's reaction. Sometimes it's an injury to your skin or a bad sunburn. It could be a certain medicine, like lithium or malaria drugs. An infection, particularly strep, can bring on psoriasis. So can high levels of stress.