Hair casts.

Peripilar hair casts are a pathological occurrence which is probably greater than the few reports seem to suggest. In 2 patients the authors have found fine, whitish nodular accretions of epithelial cells and keratinous debris surrounding the hair shafts of the scalp over a length of 3--7 mm located at various distances from the base of the hair along which they can freely move. Long-term or repetitive tractions incidental to modern hair styling or a moderate trichotillomania due to anxiety for hair loss are probably the causative factors.