RESUMEN
CONTEXT.: Clinical, dermoscopic, and histologic diagnostic criteria may overlap in cases with scarring and nonscarring alopecia, making diagnosis difficult for clinicians and pathologists. New histopathologic discoveries indicate that the cutaneous adnexal structural and homeostatic unit made up of the pilosebaceous unit, eccrine sweat gland coils (ESGCs), and dermal white adipose tissue may have a role in hair follicle renewal. OBJECTIVE.: To verify the presence of adipose tissue in the dermis at the level of the isthmus, infiltrating the bundles of the arrector pili muscle in biopsies from the scalp of 3 scarring alopecias: frontal fibrosing alopecia (FFA), fibrosing alopecia in a pattern distribution (FAPD), and lichen planopilaris (LPP). DESIGN.: We performed a retrospective and descriptive survey of 71 female scalp biopsies from 2016 to 2022 diagnosed at the Dermatopathology Laboratory at Fluminense Federal University of Rio de Janeiro. Two pathologists reviewed and diagnosed the cases, correlating pathologic features with clinical and dermoscopic findings. RESULTS.: The histopathologic findings of adipose tissue infiltration in the dermis at the level of the isthmus and in the bundles of the arrector pili muscle and the displacement of ESGCs were more frequently identified in FFA, followed by FAPD and less frequently found in LPP. CONCLUSIONS.: According to our research, adipose tissue infiltration in the dermis at the level of the isthmus and in the bundles of the arrector pili muscle and the displacement of ESGCs were observed in 3 scarring alopecias (FFA, FAPD, and LPP) and seems to be involved in the development of scarring alopecia.
Asunto(s)
Tejido Adiposo , Alopecia , Cicatriz , Glándulas Ecrinas , Fibrosis , Liquen Plano , Humanos , Alopecia/patología , Femenino , Liquen Plano/patología , Liquen Plano/diagnóstico , Estudios Retrospectivos , Cicatriz/patología , Tejido Adiposo/patología , Glándulas Ecrinas/patología , Fibrosis/patología , Persona de Mediana Edad , Adulto , Cuero Cabelludo/patología , Folículo Piloso/patología , Anciano , BiopsiaRESUMEN
Trichodynia refers to the painful sensation of the scalp related to the complaint of hair loss. Originally suggested to be distinguishing for telogen effluvium and related to hair loss activity and follicular inflammation, further studies have found trichodynia to be common in androgenetic alopecia as well and coexisting with psychopathologic findings. The respective studies failed to demonstrate correlations between trichodynia and quantifiable hair loss activity, nor histopathologic evidence for follicular inflammation. A symptomatic scalp is a frequent condition in specific dermatological conditions of the scalp. By definition of exclusion, we are not dealing with trichodynia in these cases. It is conceivable that neuropeptides are key players between the central nervous system and the skin immune and microvascular system. Such mechanisms would explain the noxious effects of both external stimuli and emotional distress in eliciting cutaneous nociception. Since we have begun to understand the diverse etiologies of trichodynia, and a single term does not measure up to this circumstance, it may be wiser to describe the condition depending on the type of scalp sensation and its specific disease association. Further studies are warranted into the neural/endothelial/follicular interactions both in hair growth and shedding and the psychosomatic diseases of the hair and scalp.
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Brunsting-Perry type pemphigoid (BPP) is a rare subepidermal blistering disease and a cause of secondary cicatricial alopecia. It was originally described by Brunsting and Perry in 1957 as a rare variant of cicatricial pemphigoid, characterized by bullous lesions limited to the head, neck, scalp, and upper trunk with mild or no mucosal involvement. We report 2 cases of BPP cicatricial alopecia with histopathology of subepidermal blister formation, different clinical presentation, and different salt-split test results. One patient had features of bullous pemphigoid (BP) with important oral mucosal involvement (not yet reported in the literature), and the second patient had typical features of epidermolysis bullosa acquisita (EBA). The secondary cicatricial alopecia may be due to different antigens associated with either BP or EBA. The phenomenon of epitope spreading could explain the association between 2 distinctive bullous diseases in the same patient, justifying the divergent findings of the immunofluorescence. The specific target antigen of BPP is yet to be defined.
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A case of cutaneous graft versus host disease (GvHD) presenting as fibrosing alopecia in a pattern distribution (FAPD) is discussed, possibly providing a mechanistic model for a better understanding of the pathogenic events underlying cicatricial pattern hair loss. The implication of a follicular inflammation and fibrosis associated with patterned hair loss has emerged from several independent studies. Eventually, Zinkernagel and Trüeb reported a peculiar type of cicatricial pattern hair loss with histopathological features consistent with lichen planopilaris (LPP) associated with androgenetic alopecia (AGA). With regard to its pathogenesis, LPP is regarded to constitute a T-cell-mediated autoimmune reaction. An as yet unknown antigenic stimulus from the malfunctioning hair follicle may initiate a lichenoid tissue reaction that triggers apoptosis of the follicular epithelial cells in the susceptible individual. GvHD is a complication following allogeneic tissue transplantation and is induced and maintained by immunocompetent cells from the donor tissue that particularly attack epithelia of fast-proliferating tissues in the recipient. Due to its analogies with lichen planus, GvHD constitutes a valid immunologic model for lichen planus, LPP and ultimately FAPD. Specifically, the presentation of GvHD of the scalp combines features of AGA and of LPP, as originally proposed in earlier observations on permanent alopecia after bone marrow transplantation.