LOOSE ANAGEN HAIR

Objective: To review clinical and pathologic features and the long-ter m follow-up of patients with loose anagen hair (LAH). Design: Clinical evaluation and long-term follow-up. Setting: A university medical cen ter. Patients: Beginning in January 1990, 14 children and 5 adults (ag e range, 8 months to 47 years) were diagnosed as having LAH. Associate d diseases included alopecia areata in a 3-year-old boy and Noonan syn drome in a 5-year-old boy. Two adult patients were parents of 2 affect ed children; the other 3 adults were the only members of their familie s with LAH. These 3 patients presented with a diffuse hair shedding th at had suddenly developed 1 to 3 years before our observation. In all cases, findings of a trichogram showed a predominance of anagen hairs (80% to 100%) devoid of sheaths. Intervention: None. Results: In 4 chi ldren and 1 adult the condition remained stable; in 2 children and 1 a dult, a considerable improvement in hair density was noticed. The path ologic study of hair from 5 patients did not reveal morphological abno rmalities of the hair follicles except for a high incidence of fragmen tations of the inner root sheath. Conclusions: Analysis of our patient s with LAH reveals that the condition does not develop exclusively dur ing childhood but can occasionally manifest itself later in life. The development of LAH may be sporadic, occur in association with developm ental or acquired conditions, or, less commonly, be a familial disorde r. While adult-onset LAH may not be exceptional, it can be easily misd iagnosed as telogen hair loss. The pathologic findings of LAH do not d emonstrate any specific features and are of little value in the diagno sis of this condition.