Distinguishing Androgenetic Alopecia From Chronic Telogen Effluvium When Associated in the Same Patient

This study aimed to distinguish between androgenetic alopecia (AGA) and chronic telogen effluvium (CTE) in patients who had both conditions. The researchers used a wash test to collect shed telogen hairs and measured their length and diameter. They found that patients with AGA shed shorter and thinner telogen hairs, while those with CTE shed longer and thicker hairs. The study also found that the presence of vellus hairs (hairs 3 cm or shorter) could serve as a diagnostic tool for AGA. The method was simple, noninvasive, and suitable for office evaluation. The study concluded that counting the telogen hairs shed during a standardized shampooing and measuring the number of those hairs that are 3 cm or shorter is a good tool to diagnose the type and severity of hair loss, whether AGA, CTE, or the association of the two conditions.