title: Pili Annulati and Trichorrhexis Nodosa in the Same Patient: Cause or Coincidence?
abstract: OBJECTIVE
  To determine the relationship between pili annulati (PA) and acquired trichorrhexis nodosa (TN) seen in the same patient, considering the two main theories evoked by previous studies: greater stiffness of darker PA bands or associated cuticular damage.
  
  
  METHODS
  Light microscopy of hair shafts from different regions of the patient's scalp.
  
  
  RESULTS
  TN was not superimposed to dark bands of PA.
  
  
  CONCLUSIONS
  Greater stiffness of darker PA bands was excluded as the cause of hair breakage. Hair breakage in PA patients might be related to cuticular abnormalities, as previously reported. Because weathering of long thin chemically treated hairs is extremely common, coincidence cannot be completely ruled out in this case.
authors.affiliation: Department of Dermatology, University of São Paulo, São Paulo, Brazil.
authors.forename: Aline
authors.initials: A
authors.lastname: Donati
authors.affiliation: Department of Dermatology, University of São Paulo, São Paulo, Brazil.
authors.forename: Anna Cecília
authors.initials: AC
authors.lastname: Andriolo
authors.affiliation: Department of Dermatology, University of São Paulo, São Paulo, Brazil.
authors.forename: Marina
authors.initials: M
authors.lastname: Barletta
authors.affiliation: Department of Dermatology, University of São Paulo, São Paulo, Brazil.
authors.forename: Neusa
authors.initials: N
authors.lastname: Valente
authors.affiliation: Department of Dermatology, University of São Paulo, São Paulo, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Romiti
keywords: Hair; Hair care; Hair cosmetics; Hair disorder; Hair microscopy; Pili annulati