It’s not contagious.
Here’s a very pretty version of a condition shared by two to three percent of the population. It causes patterns, often map-like patterns, on the tongue.
Normally, the human tongue is covered with tiny papillae. These hairlike structures can look pink or white, and they look a bit like a film over the top of the tongue. But people with geographic tongue have bare patches on their tongue. These patches show darker pink or red against the rest of the tongue, and because they lack papillae they have a different texture.
Source: Do You Have A Geographic Tongue?
Tune in next time for tongues that are scalloped, fissured in addition to geographic!