spilled cough syrup on keyboard

my son spilled very little cough syrup on my macbook. Probably the littlest amount. He got scared and didn't tell me about it and wiped it clean.

Two days later my laptop functions fine, but all the keys on the keyboard are messed up. I finally ask everyone and find out what has happened.

When will i know what is the permanent damage? Is it possible that there will more damage to come in the future? I'm taking it to the apple store tomorrow morning to get a quote.

Please let me know what you think