Effects of Low-Level Laser Irradiation in a Mouse Model of Allergic Rhinitis

Evaluating the Therapeutic Potential of Microneedle Patch Laser With Multiple Wavelengths in Allergic Rhinitis: Insights From an Allergic Rhinitis Mouse Model

OBJECTIVE

There is insufficient evidence to determine the effectiveness of treating allergic rhinitis with a patch laser affix to the skin as opposed to direct intranasal irradiation of the nasal mucosa. We aimed to evaluate the effect of the microneedle patch laser with multiple wavelengths in an allergic rhinitis (AR) mouse model and its underlying mechanism.

METHODS

The microneedle patch laser was attached to the skin above the mouse's nasal cavity, transmitting light to the nasal mucosa. For 10 days, the microneedle patch laser administered simultaneous exposure to wavelengths of 670, 780, 850, and 910 nm at either 10 or 20 min each day. Multiple allergic parameters were evaluated following the microneedle patch laser treatment.

RESULTS

Microneedle patch laser treatment decreased allergic symptoms and inhibited OVA-specific IgE levels. Additionally, it significantly reduced eosinophil infiltration, epithelial thickness of the nasal mucosa, and IL-4 cytokine levels.

CONCLUSION

The light emitted by the microneedle patch laser attached to the skin, penetrated effectively to the nasal mucosa within the nasal cavity, suggesting potential for treating allergic rhinitis in mice and could be extended in clinical applications.

Low-Level Laser Therapy for Allergic Rhinitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Allergic rhinitis (AR) is a common allergic disorder that impairs social and physical functioning as well as quality of life. It is characterized by sneezing, rhinorrhea, congestion, and itching which respond suboptimally to drug therapy. Low-level laser therapy (LLLT) has anti-inflammatory and immunosuppressive properties that have shown promise in some studies. We aimed to systematically review LLLT's effectiveness in treating AR and meta-analyze our findings.

METHODS

A systematic search of PubMed, Scopus, and Web of Science was conducted on November 24, 2023. All studies investigating LLLT on AR were included, and a pre-post meta-analysis of nasal symptoms (rhinorrhea, nasal congestion, nasal itching, and sneezing) in the LLLT-treated arm was conducted. Rhinoconjunctivitis quality of life questionnaire (RQLQ) scores before and after LLLT were also meta-analyzed alongside a pairwise meta-analysis of LLLT with placebo, acupuncture, steroids/antihistamines, and ultraviolet lasers. A random-effects model was used with a conservative pre-post correlation of 0.4 and standardized mean difference (SMD) as the effect size.

RESULTS

Sixteen studies were included in this review, and we found that nasal symptoms are alleviated post-LLLT in people with AR (SMD: -1.4, 95 CI: [-2.07 to -1.13], p value <0.001). RQLQ scores were also reduced after LLLT (SMD = -0.72, 95 CI: [-0.94 to -0.50], p value <0.001), and very few adverse events were reported. This meta-analysis, however, had significant publication bias and heterogeneity. When compared to a placebo, LLLT did not significantly improve nasal symptoms (SMD: -0.69, p value = 0.167), which might mean the post-LLLT nasal symptom alleviation is due to a placebo effect. Comparisons to other treatment modalities were too few to deduce anything meaningful, although it does appear that LLLT is less effective than UV lasers.

CONCLUSION

LLLT is most likely effective at alleviating nasal symptomology and has a low likelihood of adverse event incidence, yet more high-quality studies with larger sample sizes are needed to compare LLLT to a placebo to ensure its superiority to the placebo effect, as well as non-inferiority clinical trials to compare it to standard treatments.

Treatment Effect of Phototherapy with Low-Level Energy in Patients with Allergic Rhinitis: A Single-Arm Observational Study

Allergic rhinitis is one of the most common health challenges and has a chronic and repetitive course that requires symptomatic treatment. We aimed to investigate the effect of phototherapy on allergic rhinitis and how long it takes to demonstrate treatment effect. Twenty-one patients who were diagnosed with allergic rhinitis using the skin prick test were enrolled. Red light (660 nm) and infrared light (940 nm) with a low power energy of 5 mW were used three times a day at intervals of at least 5 h. The Rhinoconjuntivitis Quality of Life Questionnaire (RQLQ) and a visual analog scale (VAS) were used to measure the changes in symptoms. The median RQLQ and VAS scores before treatment were 62 (49-81.5) and 3 (2-5) points, respectively. The RQLQ score improved significantly at two and four weeks after treatment (52 [39-62.5]) and 46.0 [30.5-57.0], respectively). The VAS scores also improved significantly at two and four weeks after treatment. Nasal obstruction and rhinorrhea improved significantly at one week after the procedure. Low-power (5 mW) light irradiation (660 nm red light and 940 nm infrared) was effective in improving the symptoms of allergic rhinitis. In addition, symptom improvement became clear approximately a week after use. Further studies are required to reach a definitive conclusion.

Efficacy of Low-Level Laser Therapy in a Rabbit Model of Rhinosinusitis

Little is known about alternative treatment options for rhinosinusitis (RS). We aimed to evaluate the efficacy of low-level laser therapy (LLLT) for RS in experimentally induced rabbit models of RS. A total of 18 rabbits were divided into four groups: a negative control group (n = 3), an RS group without treatment (n = 5, positive control group), an RS group with natural recovery (n = 5, natural recovery group), and an RS group with laser irradiation (n = 5, laser-treated group). Computed tomography and histopathological staining were performed for each group. mRNA and protein expression levels of local cytokines (IFN-γ, IL-17, and IL-5) were also measured. Tissue inflammation revealed a significant improvement in the laser-treated group compared with the RS and natural recovery groups (p < 0.01). In addition, sinus opacification in the CT scans and cytokine expression was reduced in the laser-treated group, though without statistical significance. LLLT could be an effective option for the management of RS concerning radiological, histological, and molecular parameters.