The efficacy and safety of Longmu Tang granule for the treatment of atopic dermatitis: study protocol for a single-centred, double-blinded, randomised, placebo-controlled trial

Background: Atopic dermatitis (AD) is a chronic relapsing skin disease that has long-term physical and mental health impacts on children with this condition. Current treatments mainly include anti-inflammatory, antibacterial, and anti-allergic interventions, systemic therapy, and recently emerging target-focused agents. However, these treatments have limited effectiveness and unwanted side effects. The use of traditional Chinese medicine (TCM) in the treatment of AD has a long history, with promising efficacies, low toxicity, and improvements in the quality of life of patients with AD. Longmu Tang granule, a TCM, has been used to effectively treat AD since 2008 through doctors' prescriptions. To scientifically evaluate the clinical efficacy and safety of Longmu Tang granule, we proposed to launch a single-centred, double-blinded, randomised, placebo-controlled trial. Methods: In this single-centred, double-blinded, randomised, placebo-controlled clinical trial conducted at Xiyuan Hospital of China Academy of Chinese Medical Sciences, a total of 60 participants will be randomly assigned (1:1) to receive the Longmu Tang granule or placebo granule for 8 weeks. The primary outcome will be evaluated using the index of Scoring Atopic Dermatitis. The secondary outcomes will be evaluated using the Children's Dermatology Life Quality Index and the number cancellation test. The mechanistic evidence will be the serum levels of inflammatory cytokines, including immunoglobulin E, tumour necrosis factor-a, interleukin-1, and interleukin-6. Discussion: The results of this trial will provide evidence of the efficacy and safety of the Longmu Tang granule and prove its anti-inflammatory action in patients with AD.