Loose Anagen Syndrome

Loose Anagen Syndrome (LAS) is a hereditary condition characterized by the easy release of anagen hairs. The underlying structural defect involves poor binding between the hair shaft cuticle and the inner root sheath cuticle, causing anagen hairs to be easily removed with gentle traction during the hair pull test. In individuals with LAS, anagen hairs are easily removed, unlike firmly rooted anagen hairs in healthy individuals. LAS mostly affects children, with 90% of patients showing improvement over time. Periodic episodes of excessive hair shedding may be the only identifiable symptom, and hair breakage should not be an issue.

The classic presentation is a young girl with short, blonde hair that is less dense than normal, slow-growing, and easily plucked. However, other presentations include patches of unruly hair that are easy to extract or hair that appears normal but is easily pulled from the scalp. Topical or oral minoxidil can help prolong the anagen phase and treat loose anagen syndrome.