Hormones and clocks: do they disrupt the locks? Fluctuating estrogen levels during menopausal transition may influence clock genes and trigger chronic telogen effluvium.

Chronic telogen effluvium describes the clinical condition noted mostly in middle-aged women of increased, diffuse scalp hair shedding that is prolonged and often presents with a fluctuating course that may continue for years but does not lead to visible hair thinning. Despite its description almost 20 years ago, the underlying pathologic cause of CTE is yet to be identified. However the culmination of research in the field of hair biology and the burgeoning field of chronobiology may lead to exciting breakthroughs in our understanding of CTE. In this paper the current literature on CTE is reviewed and a hypothesis is put forth that CTE may be triggered by hormonal fluctuations and alterations in circadian control genes.