Seventy‐MHz Ultrasound Detection of Early Signs Linked to the Severity, Patterns of Keratin Fragmentation, and Mechanisms of Generation of Collections and Tunnels in Hidradenitis Suppurativa

Abstract

Objectives-To test the capability of 70-MHz ultrasound for detecting initial ultrasound signs of hidradenitis suppurativa (HS) linked to severity.Methods-A cross-sectional study of the ultrasound images of patients with HS was conducted and compared with a healthy control group. Detection and identification of early subclinical ultrasound signs in the lesional and perilesional areas of the HS cases in comparison with the control group were performed. Statistical analyses included mean, dispersion measures, the Kruskal-Wallis test, and bivariate and multivariate ordered logistic regression studies. Significance was assessed at P < .05.Results-A total of 139 patients with HS met the criteria and showed abnormalities of the hair follicles such as a curved shape, ballooning, and protrusion into pseudocysts, collections, or tunnels (donor of keratin sign). Significant increases in the sizes of the hair follicles and hair shafts were found in HS cases. The following ultrasound signs were significantly linked to severity: a connecting band between the base of adjacent hair follicles (bridge sign), a fragment of the hair shaft extruding through a dilated hair follicle (sword sign), and retained cylindrical fragments of keratin in the dermis. Two patterns of fragmentation of the keratin were detected: multifragment and cylindrical.Conclusions-Ultrasound can detect early HS signs that are significantly linked to severity and 2 types of fragmentation of the keratin, which could support the generation and perpetuation of the fluid collections and tunnels. These ultrasound signs can help prompt diagnosis and management, the development and testing of medications, and the measure of treatment outcomes in HS.

Sonographic Evaluation of Hidradenitis Suppurativa with Smartphone-Linked Portable Ultrasound

“…Thus, the true rate of subclinical lesions per patient was possibly higher than what we detected. Furthermore, the conventional US machines used in HSUS research typically have a peak frequency range of 15–22 MHz, with some reaching as high as 70 Mhz (very-high-frequency US) [10]. The pUS machine that we deployed has a maximum frequency of 10 MHz which may have limited the resolution of sonographic analysis.…”

Strong validation of ultrasound as an imaging biomarker in hidradenitis suppurativa

“…Although further research is needed to reproduce the results of Grand et al 4 in a multicentric context and with interrater correlations, this work expands the knowledge on HS and supports new lines of research on the management of the disease, including clinical trials. Lastly, as proven, ultrasound can support better clinical care in HS with early detection of structural abnormalities, more accurate staging and tracking of the degree of activity, 2–6,9 all of which would help provide appropriate medical and surgical management.…”

“…Ultrasound provides a unique opportunity to fill part of the pathophysiological puzzle of HS, with reliable clinimetrics encompassing both anatomical and functional changes with the use of colour or power Doppler 9 . Moreover, the higher axial resolution of ultrasound compared with magnetic resonance imaging and computed tomography makes it the first‐choice structural imaging technique in HS.…”

Color Doppler ultrasound: a standard of care in hidradenitis suppurativa

“…The detection of early signs of HS, recently reported by our group, needs special devices working with multifrequency probes that can go up to 70 MHz and have a high axial resolution of up to 30 lm. 10 This can provide detailed anatomical data in live tissues that are more comparable with histology which hopefully can support management and research, including the development of new therapies.…”