What is blue tongue disease?

????? : Bluetongue disease is a non-contagious, insect-borne, viral disease of ruminants, mainly sheep and less frequently cattle. Not really humans. Major signs are high fever, excessive salivation, swelling of the face and tongue and blueness of the tongue. Swelling of the lips and tongue gives the tongue its typical blue appearance.

Possible condition: Oral literature doesn't describe a condition with such name. Nevertheless, the tongue can show bluish or reddish in different types of diseases. In an adult like you, it could be inflammation of the blood vessels on ventral area of tongue (varicosities) due to lose of elasticity of blood vessels, showing blue through the mucosa due to venous blood irrigation.