Purpose: 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.
Procedures: 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.
Keywords: Hair; Hair care; Hair cosmetics; Hair disorder; Hair microscopy; Pili annulati.