Many people have experienced an itching sensation in their mouth when eating pineapple; in fact, many wonder if they could be suffering from an allergy. The answer, in the vast majority of cases, is no.
The cause of this tingling sensation is nothing more and nothing less than bromelain, an enzyme present in fresh pineapple, which comes into contact with the cells on the surface of the tongue.
Bromelain promotes the breakdown of proteins into amino acids so that they can be absorbed by the body, improves digestion, destroys intestinal parasites, and has anti-inflammatory properties.
But if the stinging sensation bothers you, you can avoid it by heating the pineapple or eating the part farthest from the stem, as the center of the pineapple is where the highest amount of this enzyme is concentrated.
Source: abc.es