The Role of Hair Follicle Counts and Ratios in the Histopathological Assessment of Androgenic Alopecia, Alopecia Areata and Telogen Effluvium: Does Counting 'Count'?

March 2023 in “ Human Pathology ”

Eleni Ieremia, Catherine M. Stefanato

hair follicle counts ratios androgenetic alopecia alopecia areata telogen effluvium non-scarring alopecia histopathological assessment horizontal scalp biopsies follicular counts morphologic features AGA AA TE

Studysummary This review found that while follicular hair counts and ratios assist in diagnosing non-scarring alopecia, they should be used alongside specific morphological features for accurate diagnosis.

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The document discusses the role of hair follicle counts and ratios in diagnosing non-scarring alopecia, particularly androgenetic alopecia (AGA), alopecia areata (AA), and telogen effluvium (TE). The authors conducted a literature review of English language studies on the histopathological assessment of horizontal scalp biopsies for non-scarring alopecia. The results indicate that follicular counts and ratios are useful diagnostic tools, but they should be used in conjunction with the specific morphologic features of each alopecia subtype to make a confident diagnosis.

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research Variation of Hair Follicle Counts Among Different Scalp Areas: A Quantitative Histopathological Study

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research Follicular Density and Ratios in Scarring and Nonscarring Alopecia

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This study found that follicular density and various hair growth ratios differ statistically between nonscarring and scarring alopecia, though significant overlap exists due to factors like sample size and scalp variation.

research Histopathology of Scarring and Nonscarring Hair Loss

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This review discusses histologic findings in alopecia and emphasizes the importance of understanding normal follicular anatomy and cycles in transverse sections, without reporting new results.

research An Atlas of Hair Pathology with Clinical Correlations

45 citations , May 2012 in “CRC Press eBooks”

The book helps doctors better understand and treat hair disorders due to gaps in their training.

research Histopathologic Features of Alopecia Areata Incognito: A Review of 46 Cases

34 citations , February 2012 in “Journal of Cutaneous Pathology”

This research retrospectively evaluated 92 skin specimens to propose histopathological criteria for diagnosing alopecia areata incognito, distinguishing it from telogen effluvium and androgenetic alopecia.

research Histopathology of Alopecia: A Clinicopathological Approach to Diagnosis

170 citations , December 2009 in “Histopathology”

This review discusses the histopathological diagnosis of scarring and non-scarring alopecias, emphasizing the importance of adequate tissue sampling and clinical information; it reports no new empirical results.

research Hair Counts in Scalp Biopsy of Males and Females with Androgenetic Alopecia Compared with Normal Subjects

40 citations , June 2009 in “Journal of Cutaneous Pathology”

This study found that Iranian patients with androgenetic alopecia had a higher terminal to vellus hair ratio compared to previous studies in Whites, suggesting potential onset of miniaturization.

research Follicular Streamers (Stelae) in Scarring and Non-Scarring Alopecia

29 citations , July 2008 in “Journal of Cutaneous Pathology”

This study found that follicular streamers are mostly present in non-scarring alopecia cases, and tracking their location can improve diagnosis accuracy.

research The Histopathology of Noncicatricial Alopecia

43 citations , March 2006 in “Seminars in Cutaneous Medicine and Surgery”

This review examines the histopathologic features of four common types of noncicatricial alopecia and reports no new clinical results.

research Hair Density in African Americans

129 citations , June 1999 in “Archives of Dermatology”

This study found that hair density is significantly lower in African Americans compared to whites, which may affect the evaluation and diagnosis of scalp biopsy specimens in this population.

research Chronic Telogen Effluvium: Increased Scalp Hair Shedding in Middle-Aged Women

234 citations , December 1996 in “Journal of The American Academy of Dermatology”

The authors concluded that chronic telogen effluvium in middle-aged women presents distinct clinical and histological features that differ from androgenetic alopecia and acute telogen effluvium.

research Histopathology of Non-Scarring Alopecia

122 citations , April 1995 in “Journal of Cutaneous Pathology”

The document describes how to tell different types of non-scarring hair loss apart by looking at hair and scalp tissue under a microscope.

research Diagnostic and Predictive Value of Horizontal Sections of Scalp Biopsy Specimens in Male Pattern Androgenetic Alopecia

309 citations , May 1993 in “Journal of The American Academy of Dermatology”

This study concluded that horizontal sections of scalp biopsy specimens provide more diagnostic information for male pattern androgenetic alopecia than vertical sections and can predict hair regrowth potential following topical minoxidil therapy.

research Hair Anatomy for the Clinician

139 citations , July 1991 in “Journal of The American Academy of Dermatology”

This article discusses the structure of hair follicles and their significance in evaluating hair disorders, but it does not report any new research findings.

research The Transverse Anatomy of Androgenic Alopecia

42 citations , December 1990 in “The Journal of Dermatologic Surgery and Oncology”

This study found decreased hair density and altered follicular architecture in the balding frontal scalp of patients with androgenic alopecia, with increased vellus hairs noted.