Background: Alopecia mucinosa (AM) or follicular mucinosis (FM) are used many times interchangeably to describe the accumulation of mucin in the follicular epithelium. FM may be preferable when the presence of mucin is not associated with alopecia. The NAHRS classified AM among the primary lymphocytic scarring alopecias. AM has been described in correlation with a variety of malignancies and benign conditions. While benign AM are more common in childhood, most cases of AM are encountered in adults where an association with a lymphoproliferative disorder (LYPD) occurs in 30% of patients.
Objective: To demonstrate that FM may mimic different patterns of hair loss.
Methods:
Case #1 - A 14 y/o healthy teenager giving a seven year history of a bald spot on her scalp that had re-grown hair and reformed repeatedly. She denies any local symptoms and takes no medications. O/E: On the frontal scalp an alopecic patch 2cm in diameter, partially covered with tapered and broken hairs of varying length. A biopsy confirmed the diagnosis of trichotillomania. In addition follicles were permeated with mucin which is not characteristic for this condition. A workup excluded the possibility of a LYPD.
Case #2- A 58 y/o woman giving a six year history of hair loss involving the hair line, accompanied by occasional pruritus. PMHx: anxiety and osteoporosis. O/E: The hair line showed features of scarring as well as pinkish ill-defined areas covered with hairs. Two biopsies confirmed the diagnosis of FM with a follicular non-atypical, non-lichenoid lymphoid infiltrate, which was polyclonal by PCR.
Conclusions:
• FM may represent a secondary change in trichotillomania
• FM can be a mimicker of frontal fibrosing alopecia
• Long term f/u of adult onset FM is mandatory to exclude development into a LYPD.
• Routine stains for mucin are important in scalp biopsies