Discussion

Long COVID, a cluster of persistent COVID-19-related problems, known as persistent symptoms after the acute outcome of COVID-19 [1-3]. This study aims to evaluate the therapeutic effects of cheek acupuncture on long COVID symptoms, and its ability to reduce the diverse and severe manifestations of long COVID. Our findings demonstrate that cheek acupuncture could be a promising approach to manage long COVID symptoms, particularly related to fatigue, palpitations, sleep disruption, pharyngeal discomfort, shortness of breath, and cough.

The symptoms associated with long COVID are rather complex as they imply the cooperation of several organs and substantially reduce the quality of life of patients. Office for National Statistics in the United Kingdom reported that about 2.9% of the country's population had suffered from long COVID symptoms for more than 4 weeks [13]. In our study, the most common symptoms admitted by the 40 patients were fatigue (70%), palpitations (37.5%), sleep disturbances (30%), pharyngeal discomfort (30%), shortness of breath (25%) and cough (25%), which correspond to commonly reported symptoms in the literature [4,13]. These symptoms are not only physically detrimental, but they also have a critical psychological impact on people and can lead to a decrease in their work capacity and general well-being.

The long COVID`s pathophysiology is complicated and not thoroughly understood yet. But an increasing body of evidence indicated autonomic nervous system dysfunction as a pivotal factor in long COVID persistence. Studies have indicates that there is a significantly higher probability of autonomic dysfunction in those with persisting symptoms from long COVID, ranging from 37.5% to 67% [14-16]. Autonomic dysfunction and long COVID share many symptoms. Dizziness, tachycardia, sweating, headache, and “brain fog” are some of the symptoms [17]. It may be caused by the invasion of viruses to autonomic centers, autoimmunity, persistent inflammation, hypoxia, overactive sympathetic system, and renin-angiotensin system imbalances [18]. The similarities provide a theoretical foundation for a treatment approach towards autonomic regulation.

Cheek acupuncture is a new treatment for long COVID symptoms. It is developed by Dr. Yongzhou Wang. It represents a unique treatment strategy based on the physical-mental theory of Western medicine, the biological holographic theory, the anatomical structure of the human body, and the Qi pathway of traditional Chinese medicine. The practice assumes that certain points located at the cheek correspond to a set of various functions in people and are therefore capable of achieving therapeutic effects [5]. Previous studies have demonstrated the efficacy of cheek acupuncture for control of pain [6,7], treatment of conditions such as cardiac syndrome X [8], cervical insomnia [9], migraine [10], allergic rhinitis [11], and functional dyspepsia [12]. The similarities between these conditions and long COVID indicate that cheek acupuncture may have a broad therapeutic application for long COVID.

In our study, the pressing pain noted on physical examination was mostly located in the neck, supraclavicular fossa, thoracic and lumbar spine, and abdomen. These regions include important anatomical characteristics of the autonomic nervous system, specifically the cervical sympathetic chain, thoracic sympathetic fibers, and celiac ganglion. The easing of symptoms such as fatigue, palpitations, sleep disturbances, pharyngeal discomfort, shortness of breath, and cough, with an effective rate of 100%, indicates that cheek acupuncture may be able to regulate autonomic function by normalizing symptoms at anatomical sites. The fact that there were no major side effects or complications during the entire treatment period further confirms the remarkable safety and tolerability of this therapy.

The biological holographic model may explain the underlying mechanism that applies to long COVID. Wang et al. [6] proposed the theory of biologic holographic model. The signals of local injuries can be sensed and analyzed by homunculi at local cheek, spinal cord, and cerebral cortex levels. Acupuncture on the cheek activates these homunculi. Thus, the autonomic nervous system is regulated, and symptoms are finally relieved. A systemic regulatory function of cheek acupuncture establishes a broad therapeutic effect on different symptoms of long COVID.

Although our study achieved good results, there were some limitations. It was concerned the small sample size and the non-double-blind design might affect the generalizability of the study results. It’s also known that the follow-up after infection with COVID-19 occurs in a relatively short period, thus, it could be spontaneous recovery. Ideas for future research should involve expanding the sample size, a randomized double-blind controlled design, and extending the duration of the study to evaluate the efficacy and the mechanisms of cheek acupuncture in treating long COVID.

Conclusion

Cheek acupuncture appears to be safe and effective for alleviating the symptoms of long COVID, including fatigue, palpitations, sleep disturbances, pharyngeal discomfort, shortness of breath, and cough. More research is required to investigate the mechanism in detail and to verify our findings in larger, rigorous clinical trials.