The review, led by Kyle Maas of Vanderbilt University School of Medicine together with co-first authors Anish Sharma and Sahil Kapur, synthesizes the current state of point-of-care ultrasound in hidradenitis suppurativa, or HS. The disease affects an estimated 0.05 to 4.10 percent of the population and carries a heavy burden of comorbidities, including metabolic disease, diabetes, and arthritis. First described by the French surgeon Velpeau in 1839 and named by Verneuil in 1854, HS was long misattributed to infected sweat glands. By 1975 it had been recognized as a follicular occlusion disorder, part of a tetrad that includes acne conglobata, perifolliculitis of the scalp, and pilonidal cysts. Despite rapid advances in therapy, the diagnostic delay remains stubborn, and patients who miss the therapeutic window of opportunity may suffer irreversible immune-mediated tissue destruction, secondary infections, restricted mobility, and, rarely, squamous cell carcinoma in chronically inflamed skin.

What makes ultrasound so compelling is its ability to detect disease before it becomes visible. High-frequency ultrasound operating at around 15 megahertz can identify subclinical enlargement of the deepest portion of hair follicles—changes that precede any lump or boil a patient or physician can feel. In one study cited by the review, ultrasound detected subclinical lesions in two of twelve individuals tested, and in both cases the findings changed management decisions. For people at elevated risk of HS—those with a suggestive symptom history but no overt lesions, a family history of the disease, or risk factors such as obesity, smoking, or autoinflammatory conditions—sonographic screening could theoretically prompt earlier medical intervention. The authors are careful, however, to temper expectations: detecting subclinical abnormalities is not itself an outcome, and no large-scale study has yet shown that earlier sonographic detection alters the natural history of the disease, reduces surgery or antibiotic exposure, or improves quality of life. Outside research settings, they conclude, such screening remains investigational.

Where ultrasound’s technical power truly shines is in characterizing established lesions. Each lesion type in HS has a distinct sonographic signature. Abscesses appear as hypoechoic fluid pockets, while sinus tracts—clinically synonymous with fistulas and most often visualized on ultrasound as tunnels—show up as hypoechoic channels that can be traced through the dermis and hypodermis. Hyperechoic scarring and residual hair tracts within tunnels help delineate these structures from surrounding tissue. At 15 megahertz, ultrasound can even identify tombstone comedones, the blackheads that sit atop inflamed, scarred skin bases, and granulated tissue appearing as hypoechoic oval lesions. This level of anatomic detail supports staging and severity assessment in selected patients, particularly when clinical examination alone cannot define the depth and extent of disease and surgical planning is on the table.

The review also traces the evolution of ultrasound-based severity scoring. Ten years ago, the Sonographic Scoring System of Hidradenitis Suppurativa, or SOS-HS, first proposed ultrasound criteria for the disease, and imaging of fluid collections, fistulas, and pseudocysts showed agreement with dermatologists’ clinical scores—while clinical scores tended to underestimate disease severity. Last year, a modified version, mSOS-HS, introduced two major changes. First, it shifted emphasis from the number of affected body regions to the magnitude of ultrasound activity, captured in a new Hidradenitis Suppurativa Activity score, or US-HSA, which uses standardized color Doppler to compare baseline and follow-up lesions. The US-HSA criteria evaluate perilesional echogenicity, dermal vascularity, peripheral blood flow, spread of lesions, and lesion size and appearance. Second, the system added a severity level IIIb, defined as five or more non-communicated tunnels or three or more communicated tunnels—the most severe stage, requiring urgent treatment. Still, the authors caution that formal multi-center data on interobserver agreement remain limited, and HS remains fundamentally a clinical diagnosis; ultrasound criteria are meant to complement, not replace, established clinical standards.

Beyond diagnosis and staging, ultrasound is proving valuable as a non-invasive biomarker of disease activity. Power Doppler ultrasound, which visualizes blood flow, correlates significantly with pain scores, abscess and nodule counts, the number of draining tunnels, and even the dermal inflammatory cell count on matched biopsy specimens. Ultra-high-frequency ultrasound at 48 and 70 megahertz pushes resolution further still, detecting epidermal lesions smaller than 0.1 millimeters, edema, micro-tunnels, drop lesions, and microcysts, and distinguishing pseudocysts from small fluid collections. Access to such probes, however, is confined to a small number of specialized centers, and even standard high-frequency probes remain largely restricted to academic dermatology, constraining broader implementation.

Ultrasound’s therapeutic role may be its most immediately practical contribution. Preoperative mapping with high-frequency ultrasound helps surgeons distinguish affected tissue from healthy skin before procedures such as carbon dioxide laser surgery, detecting hidden tracts and abscesses and increasing the projected area of skin excision—changes associated with reduced recurrence compared with blind procedures. Ultrasound-guided drainage of abscesses, fine-needle aspirations, core needle biopsies, and intralesional injections of triamcinolone and lincomycin all benefit from real-time imaging; preliminary work suggests ultrasound-guided intralesional therapy achieves significantly higher response rates. The review even proposes monitoring schedules: ultrasound at eight weeks for patients on antibiotics, at weeks four, twelve, and twenty-four for those on biologics, and at multiple time points around surgery to evaluate post-surgical recurrence. These interventions are generally well tolerated, though small procedural risks such as infection, bleeding, or reactions to local anesthetic exist, and some patients with advanced disease report mild to severe discomfort during the examination itself.

To help clinicians navigate this expanding landscape, the authors propose a three-tier framework. The first tier comprises established, selectively useful applications: preoperative mapping for surgical excision, ultrasound-guided drainage, and intralesional injection for deep or recurrent lesions. The second tier includes context-dependent uses such as treatment monitoring with the US-HSA framework, severity staging beyond the Hurley classification, and characterization of lesion components—applications with biological plausibility but predominantly single-center evidence. The third tier is frankly investigational: deep learning-based image interpretation, smartphone-linked portable sonography, contrast-enhanced ultrasound using agents such as hydrogen peroxide to outline tracts, shear wave elastography to measure fibrosis and stiffness, and correlation of sonographic findings with cytokine biomarkers like IL-23, IL-17a, and IL-17F. None of these has been externally validated in independent HS cohorts, and smartphone-linked devices in particular currently show diagnostic accuracy too poor for clinical use.

Compared with alternatives such as magnetic resonance imaging, PET-CT, and infrared thermography, ultrasound offers real-time imaging without ionizing radiation at lower per-examination cost. Yet the review is emphatic that ultrasound is not a universal first-line modality: MRI remains preferred for severe, deep, or anogenital disease and extensive perineal involvement. Practical barriers loom large—comprehensive sonographic evaluation takes more clinic time than physical examination, no formal cost-effectiveness analyses exist, high-frequency probes are frequently unavailable in community practice, and reimbursement for cutaneous ultrasound remains uncertain. The feasibility of routine ultrasound assessment, the authors warn, may be substantially overstated outside specialized centers.

The deepest unresolved question is whether any of this imaging actually makes patients better off. Existing evidence focuses on surrogate endpoints—lesion characterization, staging, monitoring—rather than patient-centered outcomes such as HS Clinical Response, IHS4 scores, recurrence after surgery, medication stewardship, or dermatology-specific quality of life. No study has yet demonstrated that ultrasound-guided management improves such outcomes, leading the authors to describe the technology’s value as plausible but unproven. Two questions should guide future research: in which clinical scenarios does ultrasound change management beyond what examination alone would produce, and do those changes withstand longer-term follow-up and translate into genuine benefit? As artificial intelligence matures—deep learning algorithms already match or exceed the diagnostic accuracy of primary care physicians and approach that of dermatologists for skin conditions—and as 3D reconstruction, cryotherapy mapping, and multimodal imaging with MRI and CT advance, ultrasound’s role in HS could expand dramatically. For now, the message is measured: a powerful tool is finally seeing what clinicians could not, but proving it helps patients is the next, essential step.

Subject of Research: Point-of-care ultrasound imaging for the diagnosis, staging, and treatment planning of hidradenitis suppurativa

Article Title: Point-of-care ultrasound in Hidradenitis Suppurativa: applications for diagnosis, staging, and treatment planning

Article References: Maas, K., Sharma, A., Kapur, S., Kaakarli, H., Tadrousse, K., Sidhu, K. S., Verma, K. K., Unver, L., & Burkhart, C. G. (2026). Point-of-care ultrasound in Hidradenitis Suppurativa: applications for diagnosis, staging, and treatment planning. Archives of Dermatological Research, 318(1), Article 487. https://doi.org/10.1007/s00403-026-04984-y

Image Credits: AI Generated

DOI: 10.1007/s00403-026-04984-y

Keywords: hidradenitis suppurativa, ultrasound, high-frequency ultrasound, color Doppler, US-HSA score, preoperative mapping, dermatology, diagnostic imaging, sinus tracts, artificial intelligence, elastography, treatment monitoring