Taking a look around in the code (from work), it doesn’t look like it’s an oversight with "break;"s in disease.cpp. I am surprised not more people are encountering this bug.
@Gladius: in the @ menu, what color is the last brackets for mouth, under the ENCUMBERANCE submenu? Also, is your temperature something like “Very hot (Falling!!)”? The disease is directly related to the heat of your face (body part mouth), so it maybe so high that it is taking a long time to fall…?
Also, if you’re done with your character, you can try and adding CBM: Thermal Dissipator or something, that should regulate the temperature of your character, including your face/mouth.
@Kevin: I know a lot of stuff was done with saving/loading recently, do you think that mouth temperature doesn’t get saved/loaded correctly?