Histomorphological and Quantitative Characteristics of Black and Gray Human Scalp Hair

The objective of the present study was to understand the histomorphological and quantitative characteristics of black and gray human scalp hair. A total of 440 hair samples (220 black hairs and 220 gray hairs) were collected from 22 adult Bengalee males of West Bengal, aged between 3080 years. The hair samples were washed, scanned and measured by standard techniques. Medullary index was calculated. Comparison of medullation types revealed that continuous type of medulltion was more common (44.09%) in gray scalp hair compared to the black scalp hair (12.72%). Medullation was absent in 48.18% black scalp hair. However, the occurrence of discontinuous medulation was nearly equal in both black and gray scalp hair (39.09% vs. 38.63%). Crenate type of cuticle was more common than flattened in both types of scalp hair, although the prevalence was comparatively higher in gray scalp hair (71.80%) than black scalp hair (67.70%). Compared to the black scalp hair, gray scalp hair revealed significantly (p < 0.05) higher mean medullary diameter and medullary index. However, there was no significant difference in the mean shaft diameter between black and gray scalp hair, though, a trend of higher shaft diameter in gray scalp hair was observed.