A condition in which red splotches give the tongue a maplike appearance.
Some people see Jesus on toast, others see maps on tongues. While the former can be chalked up to an illusion, the latter points to a real medical condition.
Tiny bumps called papillae cover the tongue. Losing some of these bumps creates geographic tongue, or benign migratory glossitis, with islands of red, inflamed splotches. The condition affects 2 percent of people. Aside from a little discomfort, it’s harmless.
The cause of the condition remains mysterious, but researchers have some idea how it spreads across the tongue. Scientists report online March 31 in New Journal of Physics a computational study suggesting that geographic tongue can develop in two ways: circular and spiral.
In some cases, small spots get bigger until they cover the whole tongue. Eventually, the tongue recovers as the papillae grow back. In other cases, spiral patterns develop in recovering regions, prolonging bouts of patchiness.