I was told by a dermatologist I worked for that psoriatics (people who have psoriasis)were lucky in one respect in that they do not get skin cancer. I rarely use SPFs because I am not a burner as I have olive skin and brown eyes, and exposure to the sun helps to make the psoriasis less. My husband, who has blue eyes and fair skin, I always put SPFs on, usually around thirty. Those spray-on brands are really good, I think.