The presence of loose anagen hairs obtained by hair pull in the normal population

To help determine the specificity of "loose anagen" (LA) hairs in Loose Ana gen Syndrome, the presence or absence of LA hairs on a gentle but firm hair pull was evaluated in 110 normal subjects from a 0.5 to 83 y old. In child ren less than or equal to 10 y old, 61% had LA hairs on hair pull evaluatio n and 73% of all hairs obtained were LA hairs. In contrast, LA hairs were f ound in only two of 87 (2%) normal postpubescent subjects. The number of LA hairs was small in normal children (1-2 per hair pull) and a maximum of on e out of every 6-7 hair pulls in adults, far less than that reported with L oose Anagen Syndrome. Although the mere presence of LA hairs on a hair pull test is thus not specific for LAS in children, the number per hair pull ma y have diagnostic significance. Correlation of these findings with the vari ous hair disorder phenotypes currently termed Loose Anagen Syndrome will be important.