Hair Evaluation Method: Pull Test and Wash Test

Abstract

In women, hair loss may entail severe psychological disturbance. Hence, diagnosis needs to be assisted by a quantitative assessment. In this chapter, two simple but useful noninvasive methods are described.

The pull test should be used first in any patient complaining of hair loss and indicates the severity of the disorder. The procedure consists in dipping the fingers into the scalp hair, in four different areas, and in counting the hairs that remain entrapped. Normally, only telogen hairs are shed and, in the adults, their number does not exceed four to five for the whole scalp. The hair number and the morphology of the hair roots suggest the diagnosis of non-scarring or scarring alopecias.

The wash test (modified) consists in washing the hairs in a basin after refraining from shampooing for 5 days. All hairs collected on the basin floor (properly covered with a gauze) are counted and divided into hair shorter and longer than 3 cm. The former are considered vellus hairs. The global number of shed hairs indicate the severity of hair loss (telogen effluvium when >100), while the percentage of vellus hairs indicates the severity of androgenetic alopecia. The method permits to diagnose the association of telogen effluvium with androgenetic alopecia and to establish which of the two disorders is more severe and requires to be treated first.

Though the two methods demand to be performed according to a strict standardized procedure, they are simple, cheap, noninvasive, and useful in the office.