Efficacy and Safety of Acupuncture Combined With Chinese Herbal Fumigation in the Treatment of Chronic Non-Specific Neck Pain: A Multicenter Randomized Controlled Trial

Background and Rationale Chronic non-specific neck pain is a prevalent musculoskeletal condition and a leading contributor to disability worldwide. It is characterized by persistent pain, stiffness, and functional limitation without a clear underlying structural pathology. Although conventional treatments such as non-steroidal anti-inflammatory drugs, physical therapy, and exercise are widely used, their effectiveness is often limited and may be associated with adverse effects. Traditional Chinese medicine offers alternative therapeutic strategies, including acupuncture and herbal fumigation. Acupuncture is believed to unblock meridians and regulate pain pathways, while Chinese herbal fumigation combines thermal stimulation with transdermal absorption of medicinal components to improve local circulation and reduce inflammation. Despite their complementary mechanisms, high-quality randomized controlled trials evaluating the combined effect of these two therapies for chronic non-specific neck pain remain scarce. This study aims to address this gap by rigorously assessing the efficacy and safety of acupuncture combined with a standardized herbal fumigation formula.

Study Design and Setting This study is a multicenter, randomized, parallel three-arm controlled clinical trial. It will be conducted at two traditional Chinese medicine outpatient centers in Malaysia. The study will enroll 120 eligible participants who will be randomly allocated in a 1:1:1 ratio to one of three groups: (1) acupuncture combined with Chinese herbal fumigation, (2) acupuncture combined with sham fumigation, and (3) acupuncture alone. An assessor-blind design will be employed to minimize bias, meaning that outcome assessors and data analysts will be unaware of group allocation.

Participants and Eligibility Participants will be recruited from outpatient clinics, bulletin boards, and online health platforms. Eligible individuals must be aged 18 to 65 years, have chronic non-specific neck pain lasting at least three months, present with a Visual Analog Scale score of 4 or higher, and demonstrate a reduction in cervical range of motion of 20% or more. Both Western diagnostic criteria and traditional Chinese medicine pattern differentiation for "cold coagulation type" neck pain must be met. Key exclusion criteria include confirmed organic pathology (e.g., disc herniation, infection, tumor), severe systemic diseases, pregnancy, lactation, receipt of other neck pain treatments within the past month, open wounds or skin lesions in the treatment area, and known allergies to acupuncture needles or herbal components.

Interventions The treatment period consists of five sessions delivered over three weeks, approximately twice per week. A follow-up assessment will be conducted four weeks after the final treatment.

Acupuncture Combined with Chinese Herbal Fumigation Group: Participants receive acupuncture at bilateral cervical Jiaji points (EX-B2) using single-use sterile needles (0.30 × 40 mm). Needles are retained for 20 minutes with manipulation to achieve deqi. Fumigation is performed using the Wenyang Tongluo Fumigation Formula, a proprietary herbal blend prepared as a powder (30 g) and decocted with 1000 mL of water. Participants lie supine while the neck area is exposed to steam from a fumigation bed. The steam outlet is positioned 30 cm from the neck, with temperature controlled: 35°C for 3 minutes, followed by 40°C for 30 minutes.