Dermal fibrosis in male pattern hair loss: a suggestive implication of mast cells

Abstract

A relationship has been suggested between mast cells (MCs) and male pattern hair loss (MPHL), because of histological evidence of perifollicular fibrosis and increased mast cell numbers. Two paired punch biopsies were taken from balding vertexes and non-balding occipital promontory areas of ten patients with MPHL (Ludwig-Hamilton IIIv to IV) and from five normal subjects aged from 20 to 35 years. Masson trichrome and Victoria blue staining were performed to observe collagen frameworks and elastic fiber structures. Numbers of immunoreactive MCs stained with anti-tryptase or anti-chymase antibody were counted. It was found that collagen bundles were significantly increased in balding vertexes than in non-balding occiput scalp skin. A near 4-fold increase in elastic fibers was observed in both vertex and occiput scalp skins with MPHL versus controls. Total numbers of MCs (tryptase-positive) in site-matched scalp samples were about 2-fold higher in MPHL subjects than in normal controls. Percentage elastic fiber (%) was found to be relatively well-correlated with tryptase and chymase-positive MCs. These findings suggest that accumulated MCs might be responsible for increased elastic fiber synthesis in MPHL, and indicate that future investigations are warranted.

Clinical, Histological and Trichoscopic Correlations in Scalp Disorders

“…AGA is a transitional alopecia, because of its scarring evolution [38]. It is characterized by anisotrichia, miniaturized hair, yellow dots, circle hair, brown halo and empty follicles.…”

Critical care and survival of fragile animals: The case of Prrxl1 knockout mice

“…The neuropeptide substance P increases mast cell degranulation and accelerates hair follicle regression in a murine model of the autoimmune hair loss (Siebenhaar et al, 2007). Interestingly, increased numbers of activated mast cells have also been documented in scarring alopecias in humans, including male pattern baldness (Xu et al, 2003;Won et al, 2008). Thus, we suggest that the onset of hair loss in the knockout animals is due to a constitutive exaggerated itch sensation, but that the cage enrichment is able to prevent the escalation of grooming from compulsive scratching to skin biting that leads to skin wounds.…”

Trichoscopy in anagen effluvium: Extensive peripilar sign

“…Thus, prolonged chemical exposure could be a causative factor for peripilar sign in anagen effluvium as mentioned before [5,6].…”

“…Although perifollicular inflammation is known to be the cause of peripilar sign; its etiopathogenesis is still unknown in its entirety. It has been postulated that perifollicular inflammation could result due to the effect of ultraviolet rays, chemical exposure, melanocytes etc [5,6].…”