Effect of Abrocitinib on the Skin Microbiome in Patients With Moderate-to-Severe Atopic Dermatitis
In brief
Abrocitinib 200 mg cuts Staphylococcus aureus and raises skin diversity in atopic dermatitis
In a 12-week trial of 43 patients with moderate-to-severe eczema, the higher dose of abrocitinib reduced the relative abundance of Staphylococcus aureus and increased overall microbial diversity, with changes evident by week 2 and continuing to week 12. These microbiome shifts paralleled clinical improvement and favorable immune-marker changes, suggesting the drug's benefit may involve restoring a healthier skin ecosystem.
- Journal
- Allergy (Q1)
- Published
- 2 August 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Madeline Kim, Ester Del Duca, Joel Correa Da Rosa, Juliana Pulsinelli, Yeriel Estrada, Dan Xu, et al.
- PMID
- 42543003
- DOI
- 10.1111/all.70467
Why clinicians should know about it
- Picked for Microbiology (medical) (top studies of the week, 9 August 2026): Abrocitinib alters skin microbiome composition in AD
- Picked for Dermatology (top studies of the week, 9 August 2026): Abrocitinib effects on skin microbiome in moderate‑to‑severe atopic dermatitis
- Picked for Immunology and Allergy (paper of the day, 3 August 2026).
Abstract
BACKGROUND: Atopic dermatitis (AD) is characterized by microbial dysbiosis, notably an overabundance of Staphylococcus species. This study aimed to evaluate the effects of abrocitinib, a Janus kinase 1-selective inhibitor, on the skin microbiome and clinical outcomes in patients with moderate-to-severe AD. METHODS: Patients enrolled in JADE MOA (NCT03915496) were randomly assigned to receive once-daily abrocitinib (100 or 200 mg) or placebo for 12 weeks. Skin swabs collected at baseline and Weeks 2, 4, and 12 underwent 16S rRNA gene amplicon sequencing to determine microbial composition. Disease severity was assessed at the same time points using established clinical metrics. Associations between microbial abundance and clinical metrics, as well as inflammatory and skin barrier markers, were investigated. RESULTS: Data from 43 patients were included. Alpha diversity increased significantly at Week 12 of treatment with abrocitinib 200 mg. Beta diversity analysis revealed clustering of the abrocitinib groups away from placebo as early as Week 2; divergence continued through Week 12. Staphylococcus and S. aureus relative abundance decreased in a dose-dependent manner from Week 2 through Week 12 of abrocitinib treatment. Changes in skin microbial composition corresponded with improvements in clinical metrics of disease severity as well as immune markers of AD. CONCLUSIONS: Abrocitinib treatment is associated with beneficial changes in the skin microbiome, notably a reduction in S. aureus and increased microbial diversity. These findings provide insight into the mechanism of action of abrocitinib and the interplay of immunomodulation and the skin microbiome in AD. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03915496.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.