Loose anagen hair syndrome

Abstract

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.

A Case of Loose Anagen Syndrome in an African American Girl

“…LAS is characterized by loose anchoring of the hair to the follicle that results in easy shedding with gentle traction . Chapalain et al postulated that a defect in a keratin gene located in the companion layer of the hair follicle may be responsible for select cases.…”

“…LAS is characterized by loose anchoring of the hair to the follicle that results in easy shedding with gentle To make this diagnosis, Tosti and Piraccini (1) recommend high clinical suspicion in addition to at least 10 hairs on the hair pull test, of which at least 70% should be in the anagen stage. Patients often report short, sparse hair that sheds easily with gentle traction and a change in hair texture, which can become unruly or dull in appearance (1,2). LAS is most commonly described in Caucasian children ages 2 to 6 years, typically blond children, although there have been reports of this syndrome occurring in children of Middle Eastern and North African descent as old as 10 years (1,4).…”

The human hair: from anatomy to physiology

“…During anagen I–V (proanagen), hair progenitor cells proliferate, envelope the growing dermal papilla, grow downwards into the skin, and begin to differentiate into the hair shaft and IRS; then, the newly formed hair shaft begins to develop and the melanocytes located in the hair matrix show pigment‐producing activity; in anagen VI (metanagen), full restoration of the hair fiber‐producing unit is realized, which is characterized by formation of the epithelial hair bulb surrounding the dermal papilla, located deep in the subcutaneous tissue, and the new hair shaft appears from the skin surface. This phase can last for several years in hair follicles …”

Hair Loss in Children, Etiologies, and Treatment

“…Loose anagen syndrome is a benign, self-limiting condition where anagen hairs are easily and painlessly extracted and mainly reported in childhood [11]. It can be seen in normal population and in alopecia areata.…”