Strawberry tongue is a physical exam finding in which the upper surface of a patient’s tongue has a distinct red coloration and a characteristic bumpy appearance because of inflammation of the taste buds. This condition is most closely associated with scarlet fever, a childhood illness that is caused by a certain type of bacteria. Toxic shock syndrome, another bacterial infection, also is associated with this tongue abnormality. Kawasaki's disease is another cause of the symptom. Strawberry tongue should be differentiated from other conditions, such as vitamin deficiencies, that can also cause tongue inflammation.
The appearance of strawberry tongue is characterized by a bright red discoloration of the surface of the tongue. It also is associated with a change in the texture of the tongue; the surface of the tongue becomes bumpier because inflammation increases the size of the tastebuds. Many people describe this finding as a looking like a strawberry because of similarities in color and texture between the tongue and the fruit. This condition must be differentiated, of course, from other causes of tongue staining, such as eating red candy or a red popsicle.
Having this tongue condition is most closely linked to a childhood illness called scarlet fever. This disease is caused by infection of bacteria called Streptococcus pyogenes. People who have scarlet fever also experience symptoms such as fever, chills, a sandpaper-like skin rash and a sore throat. It can be treated with antibiotics.
Other bacterial infections also can be associated with strawberry tongue. One is toxic shock syndrome, a disease that can be caused by the bacterial species Streptoccoccus pyogenes or Staphylococcus aureus. This syndrome can be life-threatening, causing symptoms such as fever, low blood pressure and rash.
Another cause of strawberry tongue in children is Kawasaki syndrome, also known as mucocutaneous lymph node syndrome. It causes additional symptoms such as rash, enlarged lymph nodes, eye inflammation and generalized redness and swelling of the mouth and nose. Recognizing and treating this infection is critical because it can have side effects such as the development of coronary artery aneurysms, which can be fatal.
Some other causes of tongue inflammation can mimic strawberry tongue. For example, vitamin deficiencies such as a lack of dietary vitamin B12 can cause the tongue to become red and inflamed, a condition called glossitis. Vitamin deficiencies typically do not cause inflammation of the taste buds, but they can cause erosion and irritation of the corners of the lips.