Department of Dermatology, Poznan University of Medical Sciences, Poznan, Poland.
Department of Skin Diseases, Provincial Hospital in Poznan, Poznan, Poland.
Skin Res Technol. 2021 Sep;27(5):774-784. doi: 10.1111/srt.13018. Epub 2021 Mar 10.
Primary cicatricial alopecia is a potentially irreversible process of hair loss, in which for proper diagnosis a skin biopsy is necessary. Searching for new, non-invasive diagnostic methods may shorten the time for final diagnosis, initiating appropriate treatment and reduce the need for biopsy. The aim of this study was to evaluate the usefulness of high-frequency ultrasonography (HF-USG) as a diagnostic method in patients with primary scarring alopecia and to compare it with trichoscopy.
The study covered a total of 44 adults: 8 with classic lichen planopilaris (LPP), 11 with discoid lupus erythematosus (DLE), 14 with frontal fibrosing alopecia (FFA), and 11 healthy volunteers. Each patient underwent physical and trichoscopic examination which was the base for qualification for active/inactive stage of the disease. Then, HF-USG was performed using a probe with a frequency of 20 MHz. In HF-USG images, the following elements were evaluated and measured: entrance echo (EE), follicular structures (FS), dermal background (DB), and dermal/subdermal border (D/SB).
Inactive phase was characterized by significantly lower number/lack of FS compared to the active phase of scarring alopecia. HF-USG of active LPP/FFA presented cigar-like shaped FS, while inactive stage pronounced D/SB forming saw-like pattern. Active DLE in HF-USG were associated with focal, doubled EE and widened FS with a tendency to create hypoechogenic wide, structureless bands within the skin. In inactive DLE, there was no specific pattern of D/SB or rarely puzzle-like pattern.
HF-USG images differ depending on the phase of the disease and the type of scarring alopecia, similarly to trichoscopic examination.
原发性瘢痕性脱发是一种潜在的不可逆的脱发过程，为了正确诊断，需要进行皮肤活检。寻找新的非侵入性诊断方法可以缩短最终诊断的时间，从而及时开始适当的治疗，并减少对活检的需求。本研究旨在评估高频超声（HF-USG）作为原发性瘢痕性脱发患者的诊断方法的有用性，并将其与毛发镜检查进行比较。
该研究共纳入 44 名成年人：8 名患有经典扁平苔藓（LPP），11 名患有盘状红斑狼疮（DLE），14 名患有额部纤维性脱发（FFA），11 名健康志愿者。每位患者均接受了体格检查和毛发镜检查，这是确定疾病活动/非活动期的基础。然后，使用频率为 20 MHz 的探头进行 HF-USG。在 HF-USG 图像中，评估和测量以下元素：入口回波（EE）、毛囊结构（FS）、真皮背景（DB）和真皮/皮下边界（D/SB）。
与瘢痕性脱发的活动期相比，非活动期 FS 的数量明显减少/缺乏。活动期 LPP/FFA 的 HF-USG 呈雪茄状 FS，而非活动期则呈现 D/SB 呈锯齿状。活动期 DLE 的 HF-USG 表现为局灶性、双 EE 和 FS 增宽，倾向于在皮肤内形成低回声宽、无结构的宽带。在非活动期 DLE 中，D/SB 没有特定的模式，或很少出现拼图样模式。
HF-USG 图像与毛发镜检查一样，根据疾病的阶段和瘢痕性脱发的类型而不同。
