There are many reasons for itchy tongue, the common ones are papillitis, fungal infection or allergy. 1. Tongue papillitis: mostly caused by external stimuli, inflammatory lesions, tongue papillae edema, congestion, manifested as pain, which may be accompanied by symptoms of itchy tongue. 2. Fungal infection: fungal infection on the surface of the tongue can lead to redness and itching of the mucous membrane of the tongue with white patches, and in severe cases, the patches can be connected into pieces to form a pseudomembrane. 3. Allergy: If you are allergic to certain drugs or food, you may experience allergic phenomena such as itchy tongue, which may be accompanied by itchy phenomena in other parts of the body. Itchy tongue may also have other causes such as mouth ulcers, if the symptoms are obvious or continue to be unrelieved should go to the hospital in a timely manner, improve the examination to determine the cause of the disease, standardized treatment.