Thanks for your question. There are a couple of different ways that this could be considered. First, is it something to do with the orange itself, ie, are you allergic to oranges? While this is possible, a tingling
sensation in the mouth is not generally what doctors think about when people are trying to describe an allergy. Usually an allergy will have some sort of itching, swelling, etc, and may involve other body parts and even end up with a runny nose or other similar symptoms. What you are describing doesn't quite seem to add
up to a normal allergy, although there can obviously be some exceptions and some different presentations. You should discuss it more with your doctor
. Another idea could be that it is the acid that is in the orange that is resulting in these symptoms. Many people will have an area of irritation on their tongue, whether from chronic skin conditions, smoking, chewing tobacco, or even denture trauma. This area will often be susceptible to subtle changes in the acid content of a food. It can also be one of the early signs of a tumor, and should not be ignored if it persists. Again, please speak with your doctor.