Trichotillomania is a rare form of non-scarring alopecia, mainly on the scalp, sometimes the eyebrows, which occurs as a result of conscious or unconscious, frequent hair pulling in patients that experience a significant amount of psychological stress. Clinically, the alopecic patches show bizarre, geometric shapes with retention of short hair follicles. Trichotillomania can be seen in children and in adults; while some series show a female predominance, others show no gender predilection.
Histologic findings reveal a pauci-inflammatory, non-scarring alopecia with increased catagen and telogen count. Catagen hair follicles are easily distinguished by the presence of scattered apoptotic keratinocytes in the follicular epithelium. Here, it is the mechanical trauma that is responsible for the early transition of anagen phase to catagen phase. The telogen phase tends to follow the catagen phase several weeks after the mechanical trauma has passed.
Notable histologic findings of trichotillomania are the following:
In the end, after the pathologist makes the diagnosis of trichotillomania, the hardest part of the journey has yet to begin. This is the part where the clinician supports the patient to a road of wellness. Some authors have suggested that trichotillomania should be replaced with the term “neuro-mechanical alopecia,” and I agree with this patient-centered nomenclature.
As always, thank you for taking the time to visit the monthly dermatopathology blog,
Silvija P. Gottesman, MD, FAAD
Assistant Professor of Dermatology and Pathology
Zucker School of Medicine at Hofstra/Northwell