I need a sarcasm sign. Really.

Leonard: For God’s sake, Sheldon, do I have to hold up a sarcasm sign every time I open my mouth?  
Sheldon (amazed): You have a sarcasm sign?

[…]

Sheldon: You might wanna see an otorhinolaryngologist. The throat doctor.
Penny: And why kind of doctor removes shoes from asses?
Sheldon: Depending on the depth, that’s either proctologist or a general surgeon.

Sheldon: “… oh.”