Reliability of Histopathology for the Early Recognition of Fibrosis in Traction Alopecia: Correlation with Clinical Severity

Abstract

Traction alopecia (TA) is hair loss caused by prolonged pulling or repetitive tension on scalp hair; it belongs to the biphasic group of primary alopecia. It is non-scarring, typically with preservation of follicular stem cells and the potential for regrowth of early lesions especially if traction hairstyles are stopped. However, the alopecia may become permanent (scarring) and fail to respond to treatment if the traction is excessive and prolonged. Hence, the ability to detect fibrosis early in these lesions could predict patients who respond to treatment. Histopathological diagnosis based on scalp biopsies has been used as a gold standard to delineate various forms of non-scarring alopecia and to differentiate them from scarring ones. However, due to potential discrepant reporting as a result of the type of biopsy, method of sectioning, and site of biopsy, histopathology often tends to be unreliable for the early recognition of fibrosis in TA. In this study, 45 patients were assessed using the marginal TA severity scoring system, and their biopsies (both longitudinal and transverse sections) were systematically assessed by three dermatopathologists, the aim being to correlate histopathological findings with clinical staging. Intraclass correlation coefficients were used to determine the level of agreement between the assessors. We found poor agreement of the identification and grading of perifollicular and interfollicular fibrosis (0.55 [0.23-0.75] and 0.01 [2.20-0.41], respectively), and no correlation could be drawn with the clinical severity score. Better methods of diagnosis are needed for grading and for recognition of early fibrosis in TA.

Keywords: African hair; Afro-American hair; Afro-textured hair; Dermatopathology; Minoxidil; Traction alopecia.

Fig. 1

The marginal traction alopecia severity score (M-TAS) showing regions that are assessed to provide an objective assessment of severity grading for traction alopecia (reproduced with permission from Khumalo et al. [3]).

Fig. 2

Bar graph showing clinical severity scoring of traction alopecia (TA) for 45 participants using the M-TAS score. The stage 2 score was very high in all 4 decades. Stage 4 TA was not detected in participants born between 1950 and 1980; however, a participant born between 1980 and 1990 had stage 4.

Fig. 3

Elastic van Gieson (EVG) and Masson trichrome (MT) special stains (×10) for early (a, b) and late traction alopecia (TA) (c, d). EVG shows elastic fibres on both early and late TA. MT shows thick collagen fibres. TA severity could neither be delineated using EVG (a, c) nor MT (b, d). There is loss of elastic fibres and perifollicular fibrosis in late TA (c, d).

Fig. 4

Photomicrographs of the follicular architecture of traction alopecia. a Presence of peri- and interfollicular scarring surrounding extruded, naked fragment of hair shafts. b Loss of normal follicular architecture in a longitudinal section of scalp biopsy.

Fig. 5

Photomicrographs showing fibrosis in transverse sections of traction alopecia (TA). a Follicular scar in end-stage permanent chronic TA with fibrosis at the isthmic level. b Thickened perifollicular fibrosis, loss of sebaceous glands, and inflammation.