The Effects of Lumbricus rubellus Extract on Staphylococcus aureus Colonization and IL-31 Levels in Children with Atopic Dermatitis

Abstract

Background and Objectives: The ineffective combination of corticosteroids and antibiotics in treating some atopic dermatitis (AD) cases has been concerning. The skin barrier defects in AD ease the colonization of Staphylococcus aureus (S. aureus), which results in a rise in interleukin-31 (IL-31). Lumbricus rubellus (L. rubellus) has shown antimicrobial and antiallergic effects but has not been studied yet to decrease the growth of S. aureus and IL-31 levels in AD patients. This study aimed to analyze the effect of L. rubellus extract in reducing S. aureus colonization, the IL-31 level, and the severity of AD. Materials and Methods: A randomized controlled trial (RCT) (international registration number TCTR20231025004) was conducted on 40 AD patients attending Dermatology and Venereology Polyclinic, Mother and Child Hospital (RSIA), Aceh, Indonesia, from October 2021 to March 2022. AD patients aged 8–16 who had a Scoring Atopic Dermatitis (SCORAD) index > 25, with total IgE serum level > 100 IU/mL, and had healthy weight were randomly assigned into two groups: one received fluocinolone acetonide 0.025% and placebo (control group) and one received fluocinolone acetonide 0.025% combined with L. rubellus extract (Vermint®) (intervention group). The S. aureus colony was identified using a catalase test, coagulase test, and MSA media. The serum IL-31 levels were measured using ELISA assay, while the SCORAD index was used to assess the severity of and improvement in AD. Mean scores for measured variables were compared between the two groups using an unpaired t-test and Mann–Whitney U test. Results: A significant decline in S. aureus colonization (p = 0.001) and IL-31 (p = 0.013) in patients receiving L. rubellus extract was found in this study. Moreover, fourteen AD patients in the intervention group showed an improvement in the SCORAD index of more than 35% (p = 0.057). Conclusions: L. rubellus extract significantly decreases S. aureus colonization and the IL-31 level in AD patients, suggesting its potential as an adjuvant therapy for children with AD.