Chronic telogen effluvium: Potential complication for clinical trials in female androgenetic alopecia?

Chronic telogen effluvium (CTE) is a diffuse hair thinning condition that can be mistaken for mild to moderate female androgenetic alopecia (AGA). CTE can complicate the diagnosis of milder forms of female AGA and has potentially serious implications for investigations of new hair growth agents. The erroneous inclusion of a few or more subjects with CTE, in a study population thought to consist entirely of female AGA, may be enough to distort the clinical response/efficacy results and the perceived benefit of a therapeutic/investigational agent. Therefore, subjects with CTE, alone and in combination with female AGA, should be carefully excluded from therapeutic trials involving female AGA. Obtaining a 4 mm punch biopsy specimen for horizontal sectioning for each subject about to enter a study of female AGA may make good sense.