Investigation of using very high-frequency ultrasound in the differential diagnosis of early-stage pemphigus vulgaris vs seborrheic dermatitis

Updated Role of High-frequency Ultrasound in Assessing Dermatological Manifestations in Autoimmune Skin Diseases

Autoimmune skin diseases are a group of disorders that arise due to the dysregulated immune system attacking self-antigens, causing multiple tissue and organ lesions. With disease progression, the physical and psychological health of patients may be seriously damaged. High-frequency ultrasound is non-invasive, reproducible, and suitable for visualizing the fine structure of external organs. The usage of high-frequency ultrasound has increased in recent years in the auxiliary diagnosis and monitoring of various skin diseases; it serves as a promising tool for dermatological disease assessment. This review summarizes the characteristics of high-frequency ultrasound imaging in common autoimmune skin diseases, including systemic lupus erythematosus, scleroderma, psoriasis, dermatomyositis, and pemphigus/pemphigoid. The objective of this review is to provide new ideas and strategies for dermatologists to diagnose and track the prognosis of autoimmune skin diseases.

High-frequency ultrasound as a scientific tool for skin imaging analysis

Ultrasonic imaging is one of the most important diagnostic tools in clinical medicine due to its cost, availability and good correlation with pathological results. High-frequency ultrasound (HFUS) is a technique used in skin science that has been little explored, especially in comparison with other sites and imaging techniques. HFUS shows real-time images of the skin layers, appendages and skin lesions in vivo and can significantly contribute to advances in skin science. This review summarizes the potential applications of HFUS in dermatology and cosmetology, with a focus on quantitative tools that can be used to assess various skin conditions. Our findings showed that HFUS imaging is a reproducible and powerful tool for the diagnosis, clinical management and therapy monitoring of skin conditions. It is also a helpful tool for assessing the performance of dermatological products. This technique may eventually become essential for evaluating the performance of dermatological and cosmetic products.

Ultra-high frequency ultrasound in the differential diagnosis of oral pemphigus and pemphigoid: An explorative study

OBJECTIVES

Intraoral ultra-high frequency ultrasound (UHFUS) is an emerging technique in oral medicine, due to its possibility to provide submillimeter resolution imaging of superficial mucosal structures. In this study, the potential role of UHFUS in the diagnosis of oral pemphigus vulgaris (PV) and mucous membrane pemphigoid (MMP) is assessed.

MATERIALS AND METHODS

Consecutive patients with suspected oral PV or MMP were enrolled. All patients underwent clinical examination, laboratory tests, intraoral UHFUS scan, and biopsy. Histology and direct immunofluorescence were set as benchmark for diagnosis confirmation. The sensitivity and specificity of UHFUS compared to histology were assessed. Mann-Whitney test was performed to evaluate the presence of differences in the echogenicity of PV and MMP. P-value was set at P < 0.05.

RESULTS

Twenty-five patients were included. Thirteen patients were diagnosed with PV, and twelve with MMP. The UHFUS features of PV and MMP lesions were described. Image analysis showed statistically significant differences between the echogenicity of PV and MMP lesions (P < 0.05). Good concordance between UHFUS and histology was found. UHFUS showed 75% sensitivity in the diagnosis of PV and 66.7% in the diagnosis of MMP.

CONCLUSIONS

UHFUS appears a valuable tool in the diagnosis of PV and MMP. Although histology and immunofluorescence remain the gold standard, UHFUS role in the diagnostic algorithm of PV and MMP seems promising as a chair-side tool consistently enhancing clinical evaluation of oral bullous lesions.

Investigation of using very high-frequency ultrasound in the differential diagnosis of early-stage pemphigus vulgaris vs seborrheic dermatitis

Background

Early‐stage pemphigus vulgaris (PV) often manifests as erythema alone. We hypothesized that very high‐frequency ultrasonography (VHFUS) features could simplify the differential diagnosis of early‐stage pemphigus vulgaris versus seborrheic dermatitis (SD).

Materials and Methods

Fourteen patients with SD or early‐stage PV were recruited from our outpatient clinic during 2016‐2019. We used 50‐MHz VHFUS to image the erythema on the patients’ scalp, face, chest, and back and retrospectively evaluated their ultrasonographic features.

Results

Very high‐frequency ultrasonography images of early‐stage PV showed enhanced epidermal echo (8/14, 57%), linear or oval intra‐epidermal hypoechoic/anechoic areas (12/14, 86%), linear anechoic areas at the dermal‐epidermal junction (14/14, 100%), reduced echo of superficial to whole dermis (9/14, 64%), and slightly increased dermal thickness (14/14, 100%). The intra‐epidermal hypoechoic/anechoic bands (100%) showed the greatest specificity. VHFUS images of SD showed enhanced epidermal echo (7/14, 50%), epidermal unevenness (7/14, 50%), linear anechoic bands at the dermal‐epidermal junction (8/14, 57%), reduced middle dermis echo (10/14, 71%), and slightly increased dermal thickness (10/14, 71%). The epidermal unevenness (100%) had the greatest specificity. There was a significant difference (P < .05) between early‐stage PV and SD regarding the proportion of linear intraepithelial hypoechoic/anechoic bands and linear anechoic areas at the dermal‐epidermal junction.

Conclusions

Early‐stage PV and SD have relatively specific VHFUS erythematous manifestations. Intra‐epidermal hypoechoic/anechoic bands for early‐stage PV and epidermal unevenness for SD were most specific. VHFUS contributes to the differential diagnosis of PV and SD by highlighting their features, that is, intra‐epidermal hypoechoic/anechoic bands and linear anechoic areas at the dermal‐epidermal junction.