Efficacy and safety of Soshiho-tang in atopic dermatitis patients with gastrointestinal disorders: A double-blinded, randomized, and placebo-controlled clinical trial

Because of the growing incidence of AD, psychosocial and economic burden of AD patients are often considerable. Steroid treatments are widely used, but long term use of this treatment can cause side effects. To reduce the burden of AD patients and find new efficient treatment, this study chose Soshiho-tang, a traditional medicine used in eastern Asia. Soshiho-tang (SSHT) is a traditional herbal medicine that has anti-inflammatory effects and improves immune function. This clinical trial evaluated the efficacy and safety of SSHT in atopic dermatitis (AD) patients with gastrointestinal disorders in comparison with placebo. This study was a single-center, randomized, double-blinded, placebo-controlled, and investigator-initiated clinical trial. A total of 60 patients aged 3–18 years with gastrointestinal disorders and diagnosed with AD by Hanifin & Rajka criteria with a Scoring Atopic Dermatitis (SCORAD) index between 15 and 49 were enrolled. Participants were randomly assigned to the SSHT or placebo groups in a ratio of 1:1 and efficacy evaluation was conducted at week 4 and 8. The participants orally administered SSHT or placebo three times a day for 4 weeks. The primary outcome was measured based on a change of SCORAD index. The secondary outcome measurements included the following: survey questionnaires of gastrointestinal disorder, amount and frequency of ointment application for AD, dermatology quality of life index, and safety evaluation (diagnostic test, adverse reaction, and vital sign monitoring). During efficacy evaluation, the SCORAD score and digestive symptoms in the experimental and placebo groups were not statistically significant. However, the amount and frequency of ointment application in the experimental group were reduced compared to those in the placebo group at week 8. Also, In the Children's Dermatology Life Quality Index (CDLQI), statistically significant Quality of Life (QOL) improvement was observed in the SSHT experimental group compared to the placebo group. In safety evaluation, all participants were within the normal range during the study period. Blood sample testing indicated that the lymphocytes ratio decreased, and neutrophils ratio increased in the experimental group, whereas the placebo group showed the opposite immune response pattern. We concluded that SSHT administration can reduce steroid ointment dependence and improve the QOL in AD patients by regulating neutrophil-lymphocyte ratio.