title: Lichen Planopilaris in the Androgenetic Alopecia Area: A Pitfall for Hair Transplantation.
abstract: BACKGROUND
  Classic lichen planopilaris (LPP) is a patchy form of primary lymphocytic cicatricial alopecia localized on the vertex of the scalp. It is important, however, to be aware of other, less recognized presentations that may be missed without dermatoscopy and pathology.
  
  
  RESULTS
  We report 26 patients with LPP presenting with subtle erythema and scaling colocalized in the area of patterned thinning (androgenetic alopecia, AGA). All patients had been treated for seborrheic dermatitis in the past. Dermatoscopy showed the presence of 2-4 hairs emerging as a tuft from the same ostium surrounded by erythema, peripilar casts and interfollicular scaling associated with hair miniaturization. Histopathology obtained from those areas corresponded to LPP with concomitant follicular miniaturization.
  
  
  CONCLUSIONS
  Subtle or focal cases of LPP may be missed for seborrheic dermatitis when overlapping with AGA. Dermatoscopy-guided biopsy from the affected scalp is the best approach to make a timely diagnosis. This is particularly important in patients with AGA evaluated to undergo hair transplantation, as active LPP is a contraindication for these patients.
authors.affiliation: Department of Dermatology, Miller School of Medicine, University of Miami, Miami, Fla., USA.
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Baquerizo Nole
authors.affiliation: Hair Transplant Institute of Miami, Coral Gables, Fla., USA.
authors.forename: Bernard
authors.initials: B
authors.lastname: Nusbaum
authors.affiliation: Department of Dermatology, Santa Casa Hospital and Ambulatory of Sanitary Dermatology, Porto Alegre, Brazil.
authors.forename: Giselle M
authors.initials: GM
authors.lastname: Pinto
authors.affiliation: Department of Dermatology, Miller School of Medicine, University of Miami, Miami, Fla., USA.
authors.forename: Mariya
authors.initials: M
authors.lastname: Miteva
keywords: Androgenetic alopecia; Hair transplantation; Lichen planopilaris