Retracted: Chronic Epipharyngitis Treated with Epipharyngeal Abrasion Therapy: Symptoms, Diagnosis, Pathogenesis, and Treatment Outcomes.

Chronic epipharyngitis is associated with a wide variety of symptoms, including local symptoms such as postnasal drip, sore throat, lump sensation of the pharynx, headache, chronic cough, nasal obstruction, tinnitus/ear fullness, chronic phlegm and dysphonia due to inflammation of the epipharynx, functional somatic symptoms such as chronic fatigue, dizziness, insomnia, brain fog, abdominal discomfort, and depression caused by dysfunction of the hypothalamus-limbic system via disturbances of vagal response and cerebrospinal fluid outflow, and distant organ symptoms such as immunoglobulin A nephropathy and palmoplantar pustulosis caused by the epipharyngeal lymphoid tissue as an etiologic organ. In the past, chronic inflammation in the epipharynx was difficult to prove by gross findings, now, direct observation of the epipharyngeal inflammation by endoscopy has become easier for the diagnosis. For the treatment of chronic epipharyngitis, epipharyngeal abrasive therapy (EAT), epipharyngeal application of a 1% zinc chloride solution intranasally or orally was popular since the 1960s, recently, endoscopic EAT (E-EAT), in which epipharynx is safely and accurately observed and abraded under clear vision using an endoscope, has been developed. The mechanisms of EAT effects can be classified into anti-inflammatory/antiviral effect, bloodletting effect, and vagus nerve stimulation effect. Recently, the effectiveness of EAT for post-acute sequelae of coronavirus disease 2019 (COVID-19), known as long COVID, has come into the limelight, and the number of patients for whom EAT is expected to increase. In 2019, the Japan Society of Stomato-pharyngology established the EAT Review Committee to accumulate evidence on the efficacy of EAT and to establish indications and techniques for its use. In this article, the EAT Review Committee outlines its symptoms, pathogenesis, and diagnosis of chronic epipharyngitis, technique of E-EAT, mechanisms of EAT effects, past reports for the efficacy of EAT, and a multicenter prospective study.