De Vita Valerio, Fabbrocini Gabriella
Valerio De Vita, MD, Young Dermatologists Italian Network (YDIN) Study Center of the Italian Group for Epidemiologic Research in Dermatology (GISED), Via Clara Maffei 4, 24121 Bergamo , Italy;
Acta Dermatovenerol Croat. 2018 Oct;26(3):260-261.
We have read with great interest the case report recently published in Acta Dermatovenerologica Croatica by Boer and Mihajlovic (1), which describes a 33-year-old woman with an 18-year history of classic hidradenitis suppurativa (HS) who developed HS-like lesions at the position of the bra strap. We agree with Boer and Mihajlovic: according to our clinical experience, we are convinced that mechanical stress may contribute or, in some cases, result in the development of HS. In this regard, we will describe the case of a patient with a monster hernia who presented HS-like lesions on his abdomen corresponding to the perihernial skin area, suggesting that mechanical stress was an important pathogenic factor for HS development. A 54-year-old man without any previous history of HS developed chronic, recurrent, inflammatory nodules, cysts, and depressed scars at the location of a giant abdominal hernia (Figure 1). The lesions occurred four years ago, six months after the hernia had reached its current size. Cultures from skin swabs showed commensal skin flora and moderate mixed anaerobic bacteria, as would be expected in HS lesions. No lesions occurred in other inverse areas generally affected by HS, such as the axillary and anogenito-crural regions. It is likely that the mechanical stress in the abdominal region was greater than the one occurring at the other folds due to the pressure of the trousers and belt. In fact, there are many kinds of mechanical stress: friction, pressure, pulling, tension, and pinching. Friction can be defined as the resistance to motion in the direction of the common boundary of the two surfaces. The body areas which are at greater risk for such frictional forces are mainly the skin folds, such as axillae, groins, and buttocks. There is a substantial difference between frictional and pressor stress: pressure is defined as the force per unit exerted parallel to the plane of interest. Pressure on the skin can be caused by tight dressings (2). Frictional and pressor forces can act concurrently and synergistically, starting the series of events that lead to clinical onset of HS, as most likely happened in our patient at the abdomen right below the hernia, where the trousers and belt are tightened. It is believed today that the primary event in HS is follicular inflammation: in predisposed subjects, folliculitis can develop into HS. Follicular enlargement has been observed in HS skin. It has been hypothesized that constant mechanical forces, such as pressure and friction, may lead to follicular occlusion, dilatation, microtears, and ruptures with ensuing abscesses (1-6). This case report corroborates observations from the last three decades: HS is a disease of the follicular epithelium rather than the apocrine glands (7,8), and mechanical stress, friction, and pressure may have an important role in its pathogenesis.
我们饶有兴趣地阅读了布尔和米哈伊洛维奇最近发表在《克罗地亚皮肤病与性病学学报》上的病例报告(1)，该报告描述了一名33岁患有典型化脓性汗腺炎(HS) 18年的女性，其胸罩带位置出现了类似HS的皮损。我们同意布尔和米哈伊洛维奇的观点：根据我们的临床经验，我们确信机械应力可能促使HS发生，在某些情况下，甚至导致HS的发生。在这方面，我们将描述一名患有巨大疝的患者的病例，该患者腹部对应疝周皮肤区域出现了类似HS的皮损，提示机械应力是HS发生的一个重要致病因素。一名54岁男性，既往无HS病史，在巨大腹壁疝部位出现慢性、复发性炎性结节、囊肿及凹陷性瘢痕(图1)。这些皮损于4年前出现，即疝达到当前大小6个月后。皮肤拭子培养显示为共生皮肤菌群和中度混合厌氧菌，这与HS皮损中预期的情况一致。在HS通常累及的其他屈侧部位，如腋窝和肛门生殖器区域，未出现皮损。由于裤子和腰带的压力，腹部区域的机械应力可能大于其他褶皱部位。事实上，存在多种机械应力：摩擦、压力、牵拉、张力和挤压。摩擦可定义为两个表面公共边界方向上的运动阻力。此类摩擦力风险较高的身体部位主要是皮肤褶皱处，如腋窝、腹股沟和臀部。摩擦应力和压力应力之间存在显著差异：压力定义为平行于感兴趣平面施加的单位力。皮肤上的压力可能由紧身敷料引起(2)。摩擦力和压力力可同时协同作用，引发一系列导致HS临床发作的事件，就像我们的患者在疝下方腹部裤子和腰带收紧的部位很可能发生的那样。如今人们认为HS的主要事件是毛囊炎症：在易感个体中，毛囊炎可发展为HS。在HS皮肤中观察到毛囊增大。据推测，持续的机械力，如压力和摩擦，可能导致毛囊阻塞、扩张、微撕裂和破裂，继而形成脓肿(1 - 6)。本病例报告证实了过去三十年的观察结果：HS是一种毛囊上皮疾病，而非顶泌汗腺疾病(7,8)，机械应力、摩擦和压力可能在其发病机制中起重要作用。
