Epipharyngeal Abrasive Therapy (EAT) Has Potential as a Novel Method for Long COVID Treatment

Abstract

COVID-19 often causes sequelae after initial recovery, referred to collectively as long COVID. Long COVID is considered to be caused by the persistence of chronic inflammation after acute COVID-19 infection. We found that all long COVID patients had residual inflammation in the epipharynx, an important site of coronavirus replication, and some long COVID symptoms are similar to those associated with chronic epipharyngitis. Epipharyngeal abrasive therapy (EAT) is a treatment for chronic epipharyngitis in Japan that involves applying zinc chloride as an anti-inflammatory agent to the epipharyngeal mucosa. In this study, we evaluated the efficacy of EAT for the treatment of long COVID. The subjects in this study were 58 patients with long COVID who were treated with EAT in the outpatient department once a week for one month (mean age = 38.4 ± 12.9 years). The intensities of fatigue, headache, and attention disorder, which are reported as frequent symptoms of long COVID, were assessed before and after EAT using the visual analog scale (VAS). EAT reduced inflammation in the epipharynx and significantly improved the intensity of fatigue, headache, and attention disorder, which may be related to myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). These results suggest that EAT has potential as a novel method for long COVID treatment.

Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis

“…The epipharynx is a physiologically immunoactive site, which serves as a source of antigen-specific IgA-producing B cells responsible for protective mucosal immunity [ 19 , 20 ], but hyperinflammation of the epipharynx is associated with not only local symptoms, but also the development of intractable systemic diseases such as IgA nephropathy (IgAN), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and Long COVID [ 5 , 6 , 7 , 21 ]. The excessive secretion of inflammatory cytokines associated with epipharyngitis is considered to be one of the causes, and Epipharyngeal Abrasive Therapy (EAT), which is a treatment method for chronic epipharyngitis in Japan, effectively improves these pathologies [ 5 , 10 , 22 ]. EAT reduces inflammation by scratching the entire epipharyngeal mucosa with a cotton swab soaked in zinc chloride, which has an anti-inflammatory effect ( Figure 1 ) [ 1 ].…”

“…This effectiveness of EAT is also supported by the effectiveness of the excision of the palatine tonsils, which have epipharyngeal-like lymphatic tissue, to improve autoimmune-related symptoms [ 19 , 23 ]. Although inflammation sedation by EAT is inferred from macroscopic findings using an endoscope [ 5 , 24 ], the histological changes in local immunity of the epipharynx due to EAT were unknown.…”

“…The ciliated structure of the epipharyngeal mucosa highly expresses various virus entry factors, suggesting the importance of the epipharynx in URTI [ 3 , 4 ]. Epipharyngitis is involved not only in otolaryngological disorders, but also in the development of systemic diseases such as IgA nephropathy, palmoplantar pustulosis, rheumatic arthritis, psoriasis, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and Long COVID [ 1 , 5 , 6 , 7 , 8 , 9 ]. We have previously shown endoscopically that patients with Long COVID have residual epipharyngeal inflammation [ 5 ].…”

“…Epipharyngitis is involved not only in otolaryngological disorders, but also in the development of systemic diseases such as IgA nephropathy, palmoplantar pustulosis, rheumatic arthritis, psoriasis, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and Long COVID [ 1 , 5 , 6 , 7 , 8 , 9 ]. We have previously shown endoscopically that patients with Long COVID have residual epipharyngeal inflammation [ 5 ]. Epipharyngeal abrasive therapy (EAT), which is a treatment for chronic epipharyngitis in Japan, has been reported to be effective in improving these pathological conditions [ 5 , 10 , 11 ].…”

“…We have previously shown endoscopically that patients with Long COVID have residual epipharyngeal inflammation [ 5 ]. Epipharyngeal abrasive therapy (EAT), which is a treatment for chronic epipharyngitis in Japan, has been reported to be effective in improving these pathological conditions [ 5 , 10 , 11 ]. It has been pointed out that the anti-inflammatory effect of ZnCl 2 applied to cotton swabs used in EAT with a sufficient abrasive procedure inhibit the epipharyngeal-activated lymphocytes [ 1 , 2 ], but the underlying mechanism has not been elucidated.…”