A Review of Acupuncture for Allergic Disorders: Modulation of Mast Cell Regulation via Inflammatory Pathway Suppression and Cytokine Balance

Allergic diseases represent a growing public health problem affecting millions of people worldwide, causing not only significant physical discomfort but also important psychological impacts on patients' quality of life. Among the most common conditions are allergic rhinitis, allergic asthma, atopic dermatitis, and food hypersensitivities, all characterized by excessive immune system reactions to generally harmless substances in the environment, such as pollen, mites, fungi, and specific foods. The increase in the incidence of these conditions in recent decades has been attributed to changes in modern lifestyle, environmental factors, and genetic predispositions, creating an urgent need for more effective and safer therapeutic approaches.

At the center of the pathophysiological mechanisms of allergic diseases are mast cells, specialized cells of the immune system that play a fundamental role in allergic reactions. These cells, widely distributed in tissues such as skin, respiratory tract, and gastrointestinal tract, express specific receptors for immunoglobulin E (IgE) on their surfaces. When exposed to allergens, mast cells undergo a process called degranulation, releasing inflammatory mediators such as histamine, leukotrienes, and various pro-inflammatory cytokines, including tumor necrosis factor alpha (TNF-α) and interleukins such as IL-4, IL-5, and IL-13. This cascade of events results in the characteristic symptoms of allergic diseases, including vasodilation, smooth muscle contraction, increased vascular permeability, and recruitment of other inflammatory cells.

This study represents a comprehensive review of the scientific literature that examined the therapeutic potential of acupuncture in the treatment of allergic diseases, with specific focus on the mechanisms through which this ancient Chinese medical practice may modulate mast cell function. The researchers conducted a systematic search in the PubMed and Embase databases, covering the period from January 2010 to January 2025, using specific keywords related to acupuncture, allergic diseases, and mast cells. After a rigorous screening process that included removal of duplicates and exclusion of irrelevant studies, review articles, and meta-analyses, the authors selected 365 original studies in humans and animal models that met the established inclusion criteria.

The methodology employed involved a systematic data extraction using standardized forms, focusing on information about types of allergic diseases studied, details of acupuncture interventions (including treatment protocols, selection of acupuncture points, and technical parameters), and outcome metrics related to inflammatory phenotypes and specific assays for mechanisms of action. The process included double verification to ensure the integrity and reliability of the extracted data, establishing a solid foundation for subsequent analyses of efficacy and mechanisms of action.

The results of this review revealed compelling evidence that acupuncture can effectively inhibit mast cell degranulation, resulting in significant reductions in histamine and IgE levels in patients' blood. More specifically, the studies demonstrated that acupuncture promotes a downregulation of pro-inflammatory cytokines, including TNF-α, IL-4, IL-5, and IL-13, while simultaneously increasing the production of anti-inflammatory cytokines such as IL-10. These effects are mediated through the suppression of several crucial inflammatory signaling pathways, including NF-κB, mitogen-activated protein kinases (MAPK) such as p38 and ERK, and the TLR4/MyD88 pathway.

In the clinical context, acupuncture has demonstrated significant improvements in patients with asthma, evidenced by increases in forced expiratory volume in the first second (FEV1) and peak expiratory flow (PEF), important indicators of pulmonary function. For patients with allergic rhinitis, acupuncture treatments resulted in notable reductions in nasal symptom scores and improvements in quality of life. In cases of atopic dermatitis, patients experienced significant relief of cutaneous symptoms and reduction in itching. Preclinical studies complemented these clinical findings, showing that acupuncture effectively reduces eosinophil infiltration into tissues and inhibits NLRP3/caspase-1-mediated pyroptosis, a programmed cell death process that contributes to persistent inflammation.

The clinical implications of these findings are substantial for patients and healthcare professionals. For patients suffering from chronic allergic diseases, acupuncture offers a promising therapeutic option that can be used as an adjuvant treatment to conventional therapies or, in some cases, as an alternative for those who experience significant side effects with traditional medications. The non-invasive nature of acupuncture and its relatively favorable safety profile make it particularly attractive for long-term management of chronic allergic conditions. For healthcare professionals, these results suggest that integrating acupuncture into multidisciplinary treatment protocols may enhance therapeutic outcomes and reduce dependence on anti-inflammatory medications and antihistamines, which often have undesirable side effects when used chronically.

The most commonly used acupuncture points in the reviewed studies include Danzhong (CV-17), Zhongfu (LU-1), Zusanli (ST-36), Dingchuan (EX-B1), Dazhui (GV-14), and Fengmen (BL-12), distributed mainly along the Lung, Conception Vessel, Stomach, and Bladder meridians. This selection of points is consistent with the principles of Traditional Chinese Medicine for the treatment of respiratory and allergic conditions, and the clinical data confirm their efficacy in modulating immune responses.

Despite the promising results, this review also identified several important limitations that should be considered in the interpretation of the findings. One of the main limitations lies in the methodological heterogeneity among the included studies, with significant variations in the acupuncture protocols used, including differences in point selection, needle insertion depth, stimulation techniques, and treatment duration. This variability makes it challenging to establish standardized protocols that can be consistently replicated across different clinical contexts.

In addition, many of the included studies presented relatively small sample sizes, limiting the generalizability of the results to broader populations. Methodological quality also varied considerably across studies, with some presenting limitations in experimental design, inadequate controls, or insufficient follow-up periods to evaluate long-term effects. The lack of adequate double-blind studies