High-frequency ultrasound-derived imaging biomarkers in inflammatory skin diseases

Background: Inflammatory skin diseases produce structural, vascular, and tissue-remodeling changes that may extend beyond abnormalities detectable by clinical examination. High-frequency ultrasound (HFUS), including ultra-high-frequency systems, provides noninvasive, real-time assessment of cutaneous morphology and inflammatory vascular activity. Objective: To examine HFUS in inflammatory skin diseases from an imaging biomarker perspective, emphasizing measurable structural, vascular, and mechanical features and their potential clinical applications. Key findings: Candidate ultrasound biomarkers include epidermal and dermal thickness, echogenicity, tissue interfaces, perifollicular abnormalities, fluid collections, fibrosis, architectural distortion, Doppler-detected vascularity, and tissue stiffness. Their clinical relevance is particularly evident in psoriasis, atopic dermatitis, acne vulgaris, hidradenitis suppurativa, and morphea, with emerging applications in other inflammatory dermatoses. In selected disorders, HFUS may reveal clinically occult abnormalities, while treatment-associated changes in selected parameters support their potential as candidate treatment-response biomarkers. Quantitative image analysis, elastography, and artificial intelligence may further improve reproducibility and interpretation. Conclusions: HFUS is evolving from predominantly morphological imaging toward a platform for deriving imaging biomarkers in inflammatory skin disease. Broader clinical implementation will require standardized acquisition, validated biomarkers and thresholds, operator training, and prospective evidence demonstrating clinical utility.