Loose anagen hair syndrome.

Loose anagen syndrome (LAS) is a benign, self-limiting condition where anagen hairs are easily and painlessly extracted. It is mainly reported in childhood; however, it may variably present in adulthood as well. The presence of anagen hair devoid of its sheath and with 'floppy sock appearance' is a characteristic feature of loose anagen hair (LAH) on trichogram. LAH can be seen in normal population and in alopecia areata. The percentage of LAH in LAS is more than 50%. The histopathological findings show clefting between the layers of hair and are very useful in differentiating LAS from alopecia areata. Here, a review on the diagnostic criteria and practical guidelines are discussed so as to enable the trichologist in managing this benign, self-limiting condition and differentiating it from the other causes of non-scarring alopecias.