Measuring hair lengths in a wash test

What does it mean?

It is normal to lose 50-75 hairs per day and even more on days when the hair is washed. An increase in hair shedding is seen in both the early stages of androgenetic alopecia (AGA) as well as in hair shedding disorders such as telogen effluvium (TE). Measurements of the length of hairs that are shed can provide valuable insights into whether the patient has a TE or AGA ... or both.

The shedding of a large proportion (much greater than 10 %) of hairs less than 3 cm in length is characteristic of AGA. In TE, the overall number of hairs shed is higher but hairs are typically longer (greater than 5 cm). Shedding of short hairs is not common in TE.

Non-invasive method distinguishes chronic telogen effluvium from mild female pattern hair loss: clinicopathological correlation.
Bittencourt C, et al. Int J Dermatol. 2016.

Assessing the reliability of the Modified Wash Test.
Guarrera M, et al. G Ital Dermatol Venereol. 2011.

Dr. Jeff Donovan is a Canadian and US board certified dermatologist specializing exclusively in hair loss. To schedule a consultation, please call the Whistler office at 604.283.1887

Share This