Destruction of the arrector pili muscle and fat infiltration in androgenic alopecia.
Torkamani N1,
Rufaut Norwood,
Jones L,
Sinclair R.
Author information
1
Department of Dermatology, School of Medicine and Dentistry, University of Melbourne, Carlton, Vic., Australia; Department of Dermatology, 185-187 Hoddle Street, level one, Epworth Health Dermatology Laboratory, Richmond, Vic., 3121, Australia.
Abstract
BACKGROUND:
Androgenic alopecia (Androgenetic Alopecia) is the most common hair loss condition in men and women. Hair loss is caused by follicle miniaturization, which is largely irreversible beyond a certain degree of follicular regression. In contrast, hair loss in telogen effluvium (Telogen Effluvium) is readily reversible. The arrector pili muscle (APM) connects the follicle to the surrounding skin.
OBJECTIVES:
To compare histopathological features of the APM in Androgenetic Alopecia and Telogen Effluvium.
METHODS:
Archival blocks of 4-mm scalp punch biopsies from eight patients with Androgenetic Alopecia and five with Telogen Effluvium were obtained. New 4-mm biopsies from five normal cases were used as controls. Serial 7-μm sections were stained with a modified Masson's trichrome stain. 'Reconstruct' software was used to construct and evaluate three-dimensional images of the follicle and APM.
RESULTS:
The APM degenerated and was replaced by adipose tissue in all Androgenetic Alopecia specimens. Remnants of the APM remained attached to the hair follicle. There was no fat in the normal skin specimens. Fat was seen in two of five Telogen Effluvium specimens but could be attributed to these patients also showing evidence of Androgenetic Alopecia. Quantitative analysis showed that muscle volume decreased and fat volume increased significantly (P < 0·05) in Androgenetic Alopecia compared with controls.
CONCLUSIONS:
APM degeneration and replacement with fat in Androgenetic Alopecia has not previously been described. The underlying mechanism remains to be determined. However, we speculate that this phenomenon might be related to depletion of stem or progenitor cells from the follicle mesenchyme, explaining why Androgenetic Alopecia is treatment resistant.
© 2014 British Association of Dermatologists.
PMID:
24579818
DOI:
10.1111/bjd.12921
[Indexed for MEDLINE]
View attachment 129571
the arector pili muscle gets replaced by fatty tissue from the sebaceous gland next door in Androgenetic Alopecia scalp, progressively. SO u need to do a deep wounding session to break up that fatty tissue.
hair growth-inhibitory factors, likely 15PGJ2 which binds to PPAR gamma(ups anti-flammation) and CRTH2(ups itch), secreted by Malassezia fungi as a byproduct living at the outer root shealth of the hair follicle- causes this phenomenon.
So the more malassezia fungi u have on the balding scalp, the more ppar gamma gets activated, because ppar gamma is the master regulator for lipogenesis(increases sebum and fat production) and malassezia thrive at sebum-rich skin tissue
i
m atually of the opinion that the increased 5 alpha redutase in the balding scalp is atually caused by secereted factors from malasseziai/propiones acnes in the balding scalp- likely oleic acid(found in olive oil)
Abstract
Application of new molecular and biochemical tools has greatly increased our understanding of the organisms, mechanisms, and treatments of dandruff and seborrheic dermatitis. Dandruff results from at least three etiologic factors: Malassezia fungi, sebaceous secretions, and individual sensitivity. While Malassezia (formerly P. ovale) has long been a suspected cause, implicated by its presence on skin and lipophylic nature, lack of correlation between Malassezia number and the presence and severity of dandruff has remained perplexing. We have previously identified the Malassezia species correlating to dandruff and seborrheic dermatitis. In this report, we show that dandruff is mediated by Malassezia metabolites, specifically irritating free fatty acids released from sebaceous triglycerides. Investigation of the toxic Malassezia free fatty acid metabolites (represented by oleic acid) reveals the component of individual susceptibility. Malassezia metabolism results in increased levels of scalp free fatty acids. Of the three etiologic factors implicated in dandruff, Malassezia, sebaceous triglycerides, and individual susceptibility, Malassezia are the easiest to control. Pyrithione zinc kills Malassezia and all other fungi, and is highly effective against the Malassezia species actually found on scalp. Reduction in fungi reduces free fatty acids, thereby reducing scalp flaking and itch.