Epipharyngeal Abrasive Therapy (EAT) Field Theory: A Clinical Framework for EAT in Modulating Psycho-Neuro-Endocrino-Immune (PNEI) Dynamics.

Chronic epipharyngitis/chronic nasopharyngitis has traditionally been understood as a localized inflammatory disease, but clinically, it often presents with systemic symptoms that span the nervous, immune, and endocrine systems, such as headaches, fatigue, low-grade fever, impaired concentration, orthostatic dysregulation, joint pain, anxiety, and sleep disorders. Epipharyngeal abrasive therapy (EAT) is a treatment that applies chemical and physical stimulation to the mucous membranes of the epipharynx/nasopharynx using a cotton swab soaked in a 1% zinc chloride solution. Recently, there have been increasing reports of its efficacy in controlling chronic inflammation and improving multisystem symptoms. Regarding the mechanism of action of EAT, autonomic nervous system stimulation, immune system stimulation, and endocrine system stimulation have been reported; however, many aspects of the mechanism of action remain unclear. A review of the existing research literature shows that EAT stimulates the autonomic nervous system through changes in parasympathetic activity mediated by the trigeminal-vagus reflex and has an immediate effect of inducing inflammatory reflexes. In addition, as a long-term effect, the autonomic nervous system balance is reestablished due to changes in the plasticity of the reflex pathway, chronic inflammation is controlled, and the immune response is normalized. Furthermore, continuous EAT stimulation influences the immune and endocrine systems, leading to the resynchronization of the body's homeostasis network. This article systematizes the mechanisms by which EAT exerts its multi-systemic therapeutic effects on the nervous, immune, and endocrine systems, redefines EAT from a conventional local treatment to a systemic treatment, and presents the new framework of EAT field theory. This article is presented as a narrative and conceptual review rather than a systematic review, aiming to synthesize the clinical findings and theoretical perspectives into the proposed EAT field theory.