Kenogen in female androgenetic alopecia. A longitudinal study.

BACKGROUND

Kenogen indicates the physiological interval of the hair cycle in which the hair follicle remains empty after the telogen hair has been extruded and before a new anagen hair emerges. Kenogen frequency and duration are greater in men and women with androgenetic alopecia (AGA).

OBJECTIVE

To study the relationship of kenogen with female AGA.

METHODS

A woman with AGA, studied 14 years before, was re-examined for 2 years by the phototrichogram technique. Kenogen was identified when telogen lasted 3 months and shedding left the follicle empty.

RESULTS

Kenogen lasted 1-5 months, the longest duration affecting cycles of vellus hairs, and involved more hair follicles (16 vs. 8%) than in the first observation. Cycles of vellus hairs increased in number from 4 to 13%, and cycles with a normal succession of phases decreased from 60 to 32%.

CONCLUSIONS

The number of kenogen phases increased in parallel with vellus hairs and the diminished number of normal hair cycles, features that mark AGA aggravation. Kenogen seems to be related also to the progression of female AGA.