Why care about linear hair growth rates (LHGR)? a study using in vivo imaging and computer assisted image analysis after manual processing (CAIAMP) in unaffected male controls and men with male pattern hair loss (MPHL).
BACKGROUND
The words "hair growth" frequently encompass many aspects other than just growth.


OBJECTIVES
Report on a validation method for precise non-invasive measurement of thickness together with linear hair growth rates of individual hair fibres. To verify the possible correlation between thickness and linear growth rate of scalp hair in male pattern hair loss as compared with healthy male controls.


MATERIALS AND METHODS
To document the process of validation of hair growth measurement from in vivo image capturing and manual processing, followed by computer assisted image analysis. We analysed 179 paired images obtained with the contrast-enhanced-phototrichogram method with exogen collection (CE-PTG-EC) in 13 healthy male controls and in 87 men with male pattern hair loss (MPHL).


RESULTS
There was a global positive correlation between thickness and growth rate (ANOVA; p<0.0001) and a statistically significantly (ANOVA; p<0.0005) slower growth rate in MPHL as compared with equally thick hairs from controls. Finally, the growth rate recorded in the more severe patterns was significantly (ANOVA; P ≤ 0.001) reduced compared with equally thick hair from less severely affected MPHL or controls subjects.


CONCLUSION
Reduced growth rate, together with thinning and shortening of the anagen phase duration in MPHL might contribute together to the global impression of decreased hair volume on the top of the head. Amongst other structural and functional parameters characterizing hair follicle regression, linear hair growth rate warrants further investigation, as it may be relevant in terms of self-perception of hair coverage, quantitative diagnosis and prognostic factor of the therapeutic response.
['Van Neste|Dominique|D|']
D000293:Adolescent D000505:Alopecia D016022:Case-Control Studies D003287:Contrast Media D006197:Hair D064368:Healthy Volunteers D006801:Humans D007091:Image Processing, Computer-Assisted D008297:Male D010781:Photography D012535:Scalp D012720:Severity of Illness Index D055815:Young Adult
imaging male pattern hair loss scalp hair androgenetic alopecia clinical trial phototrichogram