Clinical Efficacy and Safety of Low-Level Laser Therapy in Patients with Perennial Allergic Rhinitis: A Randomized, Double-Blind, Placebo-Controlled Trial

Allergic rhinitis (AR) is a common disease that interferes with the daily activities and reduces the quality of life. Conventional treatments often do not provide complete resolution of the symptoms, and many new treatment modalities have been tried. This study aimed to evaluate the efficacy and safety of low-level laser therapy (LLLT) for AR in a randomized, double-blind, placebo-controlled trial. Patients diagnosed with AR were randomly allocated to receive LLLT or sham treatment. The primary outcome was a change in the reflective total nasal symptom score (TNSS). The secondary outcome was quality of life scores assessed using the Rhinoconjunctivitis Quality of Life Questionnaire. Incidences of adverse events were also recorded. Among 67 randomized subjects, 41 subjects (22 in LLLT group and 19 in sham treatment group) were included for efficacy analysis. The LLLT group showed a significantly improved TNSS score compared to the sham treatment group for decreasing AR symptom severity (p = 0.011) and improving quality of life regarding nasal symptoms (p = 0.036) at the end of treatment. Throughout the treatment period, no severe adverse events occurred. This clinical trial showed that LLLT is an effective and safe option for the management of AR regarding symptom relief and quality of life improvement.