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I have gone through your query regarding pricking pain in ear and hot feeling in head. You had already being examined by ENT doctor and no abnormality in ear is detected by your doctor.
Above observation directs us to think over referred otalgia
. this is a clinical condition when patient had disease of other nearby organ but pain is felt in ear , all this happens because of similar nervous supply of that organ and ear.
In this comes-
1- Teeth.- Diseases of last molars some times gives pain to ear.
2- Posterior or back part of tongue- some times ulcers etc of back portion of tongue gives pain to ear of same side.
3- Tonsils- Some times patients of tonsillitis
feels pain in ear.
4- Eustachian tube- Dysfunction of it is well known for giving pain in ear.
5- Temporomandibular joint- Arthritis
of this joint may give to pain in ear.
So you should be examined on above lines to short out the real problem, and that may be accordingly manage.