Scalp Analysis with Multiparametric Ultrasound before and after Application of Cosmetic with Vasoconstrictor Active

Introduction: Multiparametric ultrasound (MPU) has become an increasingly valuable tool in dermatology, particularly in trichology, where it enables detailed scalp analysis beyond conventional visual assessments. By integrating B-mode imaging, Doppler flowmetry, and elastography, MPU allows for a comprehensive evaluation of scalp structures, follicular health, vascular patterns, and tissue stiffness. While widely used for diagnostic purposes, its potential for assessing cosmetic and pharmaceutical actives remains underexplored. This study aimed to determine the sensitivity of MPU in detecting real-time scalp changes following the application of a hypoxemic and vasoconstrictive cosmetic active. Perspective: Our findings suggest that MPU provides quantifiable and objective metrics for evaluating the effects of vasoconstrictive agents on scalp physiology. The fast-permeation formulation led to a significant reduction in vascular perfusion, confirmed by Doppler analysis, alongside a 32.5% increase in dermal stiffness, indicating localized vasoconstriction. Conversely, the slow-permeation formulation produced a more gradual but sustained effect, with an increase in the resistance index (RI) from 0.40 to 0.64 and a 20% increase in dermal stiffness, while hypodermal elasticity remained unchanged. These results highlight MPU as a non-invasive, real-time monitoring tool capable of assessing cosmetic and pharmacological effects on the scalp. Given its precision and versatility, MPU could become a standardized method for evaluating trichological treatments, supporting both clinical decision-making and research innovations in dermatology.