Hello Welcome in H.C.M. I have gone through your query regarding mastoiditis in your daughter. Here I would like to say that mastoid air cells may become inflammed and mastoiditis sets in. here infection reaches via- 1- External route - in these cases there is always hole in ear drum and infection reaches to middle ear and mastoid antrum through this hole in eardrum. 2- Internal route- here infection from throat reaches to ear via eustachian tube. This eustachian tube a tubular connection between middle ear and throat. 3- Vascular route- here infection reaches to mastoid air cells through blood. Whenever there is mastoiditis this may be confirmed by radiological investigations of ear as x-ray mastoid or C.T.Scan of ear. As far as treatment is concerned in cases of acute mastoiditis treatment of choice is medical (conservative), while in chronic mastoiditis treatment of choice is surgical (mastoidectomy operation). I hope your query is answered. Regards.