Introduction: TrichoScan is considered to be time-saving, easy-to-perform and consistent for quantifying hair loss/growth. Conflicting results of our study lead us to closely observe the image-analysis and certain repeated errors in the detection of hair were highlighted.
Aims: To assess utility of TrichoScan in quantification of diffuse hair loss; in males with AGA and females with diffuse telogen hair loss; with regards to total hair density (THD), telogen and vellus-hair percentages.
Methodology: TrichoScan procedure was performed on 77cases and 20controls.
Results: In cases; THD decreased with increasing severity of alopecia. Mean THD(/cm2) among male and female cases was 228 and 287 respectively. Mean telogen-hair percentages in male and female cases were 35(range: 18-57) and 33(20-54); while in male and female controls were 28(19-46) and 31(19-53). Mean vellus-hair percentages in male and female cases were 19(12-38) and 18(12-34); while in male and female controls were 17(15-19) and 17(12-22).
Discussion: Surprisingly, telogen-hair percentage was considerably high in control group. It was observed that the software breaks the hair strand into two as the hair emerges from the scalp due to difference in pigmentation; one beneath the scalp surface (analyzed as telogen) and one above. In 68% cases with obvious thinning; TrichoScan-analyzed vellus hair percentage wasn’t elevated. Also errors were noted at places where hair-strand thickness was not uniform throughout its length; where there was crossing, overlapping of the neighboring strands and when more than one hair emerged from a single ostium.
Conclusion: TrichoScan, though validated as a precise tool for measurement of hair growth parameters suitable for clinical trials evaluating treatment response; this study concludes that TrichoScan-analyzed anagen/telogen hair detection is not optimum, moreover there is overestimation of THD and vellus-hair percentage doesn’t correlate with clinical severity of alopecia. The current form of TrichoScan though easy-to-use is error-prone and awaits refinement.