Effectiveness of Cimetidine as Adjuvant Therapy in the Treatment of Acute-Extrinsic Atopic Dermatitis: A Double-Blind Randomized Controlled Trial

INTRODUCTION: Acute extrinsic atopic dermatitis (AD) requires long-term treatment. Cimetidine could be used as an adjuvant therapy for acute-extrinsic AD due to immunomodulatory effects. This study aims to assess the effectiveness of cimetidine as an adjuvant to standard treatment in acute extrinsic AD. METHODS: This is a double-blind randomized controlled trial involving 26 AD patients aged 12–60 years from 2017 to 2020. Effectiveness of cimetidine was assessed by comparing SCORing Atopic Dermatitis (SCORAD) and objective SCORAD changes in both groups at week 2, 4, 6, and 8. Serum levels of immunoglobulin E (IgE), interferon (IFN)-γ, interleukin (IL)-12, and IL-4 were also documented. RESULTS: Significant differences were observed in SCORAD changes at week 2, 4, 6, and 8 (p = 0.004; p = 0.001; p < 0.001; and p < 0.001 respectively), objective SCORAD changes at week 2, 4, 6, and 8 (p = 0.004, p = 0.001, p < 0.001, and p < 0.001 respectively), and IgE level changes at week 8 (p = 0.002) between the two groups. However, there were no significant changes in IFN-γ, IL-12, and IL-4 levels between the two groups. CONCLUSION: Cimetidine is a safe and effective adjuvant therapy for acute-extrinsic AD. TRIAL REGISTRATION: NCT04018131.