ATOPIC dermatitis (AD) is a chronic, relapsing, and remitting inflammatory skin disease. The pathogenesis of AD is multifactorial, involving skin barrier dysfunction, genetic predisposition, immunological dysregulation, and environmental factors. Additionally, recent research highlights the role of skin microbiome dysbiosis in AD. Staphylococcus aureus has been identified as a key pathogenic bacterium, while emerging studies suggest that the skin yeasts Malassezia and Candida albicans may also contribute to AD pathogenesis.
Patients with AD exhibit disrupted epidermal barriers, increased skin pH, and reduced lipid content, creating an environment conducive to microbial colonisation and infection. Current treatments for mild-to-moderate AD include oral antihistamines, topical corticosteroids, and topical calcineurin inhibitors. Given the significance of skin dysbiosis and infection risk, reducing S. aureus colonisation may improve treatment outcomes. While topical corticosteroids help normalise bacterial communities in AD lesions, the post-treatment microbiome remains distinct from that of healthy skin. Studies indicate that antimicrobial–corticosteroid combination therapy offers greater reductions in disease severity than corticosteroid monotherapy, necessitating further investigation into antimicrobial agents’ therapeutic effects on microbial balance.
Topical econazole/triamcinolone cream, which combines a corticosteroid with an antimicrobial agent, is commonly used for dermatitis associated with infections. Econazole, an imidazole antifungal, exhibits broad-spectrum activity against gram-positive bacteria and fungi, while triamcinolone serves as an effective anti-inflammatory glucocorticoid. Studies suggest that antifungal treatments can significantly alter both bacterial and fungal skin communities in inflammatory skin disorders.
This study aimed to compare the effects of antimicrobial–corticosteroid combination therapy with corticosteroid monotherapy on the skin microbiome and barrier function in AD patients. Findings revealed that both treatments effectively reduced disease severity, but the combination therapy yielded superior results in restoring bacterial microbiome balance. S. aureus abundance was notably reduced, while beneficial genera such as Cutibacterium increased. Furthermore, fungal dysbiosis in AD was observed, with an imbalance in Malassezia and filamentous fungi, which antifungal treatment appeared to partially correct.
Despite promising results, limitations include a small sample size and short follow-up period. A longer study duration and larger participant cohort are necessary to validate these findings and fully elucidate antimicrobial therapy’s role in managing AD-related microbial dysbiosis.
Katie Wright, EMJ
Reference
Tingting L et al. The effects of topical antimicrobial-corticosteroid combination therapy in comparison to topical steroids alone on the skin microbiome of patients with atopic dermatitis. J Dermatolog Treat. 2025;36(1):2470379.
