Perilymphatic fistula caused by Eustachian tube air inflation.

We present a case of a perilymphatic fistula (PLF) caused by Eustachian tube air inflation (ETAI) that was diagnosed using cochlin-tomoprotein (CTP) testing and successfully treated using transcanal endoscopic ear surgery to seal the inner ear window. A 77-year-old woman developed hearing loss and dizziness after undergoing ETAI at a local ear, nose, and throat clinic. Despite initial bed rest and steroid pulse therapy, the hearing did not improve, and transcanal endoscopic ear surgery was performed to repair the PLF. The CTP test confirmed the diagnosis of PLF, leading to a significant improvement in the patient's hearing and dizziness symptoms postoperatively. This case highlights the importance of considering PLF as a potential complication of ETAI and the value of CTP testing for diagnosing this condition.