What is causing sudden burning pain in toes?

Possible neuroma. If the pain is between the 3rd toe (middle) and the 4th toe, next to little toe, this is most likley a morton's neuroma. This is an enlargement of the nerve in this region which becomes pinched or irritated by the surrounding structures. This is also called a positive mulder's sign. Corisone injections or alcohol sclerosing injections can be helpful. Wider shoes can help, surgery last resort.