Several things may cause a sore tongue including trauma such as biting or burning the tongue, smoking cigarettes, or having a canker sore on the tongue, according to WebMD. The tongue can also get sore from anemia, diabetes or having enlarged papillae.
Many of these conditions also cause the tongue to be red, which can stem from a vitamin deficiency, WebMD states. Someone who is lacking in vitamin B12 or folic acid is at risk of having a red tongue. Another cause for a red tongue is a geographic tongue, which is sometimes referred to as glossitis. This causes reddish spots on the tongue that look like a map. Some patches of red also have whitish areas with geographic tongue. If the tongue is also sore due to this condition, topical medications are available.
Scarlet fever is a common reason for a sore and red tongue in younger children, according to WebMD. If a child has a tongue that is red and also has a fever, a pediatrician should be called right away. Antibiotics are necessary for this condition. Some children experience only the pink tongue and fever, though others also have soreness on the tongue from the condition. Scarlet fever most often occurs with children that are five years old and younger.