Short Anagen Syndrome

Short anagen syndrome (SAS) was a rarely reported condition characterized by an idiopathic short anagen phase, leading to an inability to grow long hair. Patients typically had abnormally short scalp hair and reported never having had a haircut. The condition was benign, with no associated systemic diseases or skin disorders, and hair length often improved spontaneously after puberty. SAS was not linked to hair shaft fragility or unruliness, and its main differential diagnosis was loose anagen hair syndrome (LAS).