They used to use botox where I worked to stop "gustatory sweating". I guess if you have to have your paraotid (salivary) glands removed sometimes the nerves that control them can grow back into your skin and activate your sweat glands, so every time you eat or even think about or smell something that might ordinarily make your mouth water you sweat profusely from your face instead....

They would inject botox to paralyze the nerves and stop the sweating.

The nurse I knew worked in that clinic, so I think that's how she got interested in botox in the first place.