Assessment of hair loss: clinical relevance of hair growth evaluation methods.

This review on hair growth measurement methods focuses on human scalp hair in the context of clinically relevant assessment of hair loss. This phenomenon is the end result of a complex combination of events closely associated with hair cycling followed by defective hair replacement. The methodological spectrum ranges from the most to the least invasive approach. All of the measurement methods referred to are critically reviewed, with their stronger and weaker aspects, in view of their potential application in the skin and hair clinic. The existence of recently developed highly resolutive noninvasive analytical methods capable of exploring almost every aspect of the dynamics of this growth and loss phenomenon allowed calibration of more global scoring method. From this review, the author concludes that a combination of a highly resolutive analytical approach with a global calibrated method seems advisable in the context of the monitoring of hair growth changes for better or worse, i.e. scalp hair growth or hair loss in the hair clinic.