I have a very mild form of psoriasis. Note: It.is.not.contagious. Most people don't even notice I have it because it's kept under control. There's just a very small patch on my hairline off to the side, about a dime in diameter, and because it's exposed all the time, I make sure that heavy doses of medicated cream go on it. Thus no dryness, no itching, and most of all, no scaling at all. It just looks a little pinker than the rest of my face.
Me: You guessed it
SC: Stupid cashier
SC: "That will be $xx.xx, please."
Me: *takes credit card out of wallet. Looks up and notices SC is staring at my forehead*
Me: "Uh... did you want to ask a question or something?"
SC: *in horrified tone* "Are you diseased?"
Me: "Pardon me?"
SC: "That... that thing on your forehead."
Me: *silently sighing* "It's psoriasis. It's a skin disorder. It's very similar to eczema."
SC: "Oh." *still staring at my forehead* "That just looks gross."
Me: *evil thoughts running through head* "Yes, it's pretty awful. Oh, I should have mentioned, you'd best wear gloves or something, because I don't want to see you catch it, either."
SC: *absolutely horrified look*
Me: "In fact, the virus that causes it is highly communicable. It's an airborne virus."
Then I fake a very, very loud sneeze directed towards the floor, but covered my mouth. Then I grab her pen and sign my credit card receipt, take my copy and leave with a smirk on my face.
Yes, gross and immature, I know, but I've had enough of stupid idiots this week.