BACKGROUND: The hair pull test lacks validation and has unclear pretest guidelines. OBJECTIVE: We sought to quantify normal hair pull test values and elucidate the effect of pretest hair washing and brushing. The impact of hair texture and lifestyle was also examined. METHODS: Participants (n = 181) completed a questionnaire recording demographics, medications, and hair health/history. A single hair pull test (scalp vertex) was performed. RESULTS: The mean number of hairs removed per pull was 0.44 (SD 0.75). There was no significant difference in the mean number of hairs removed regardless of when participants washed (P = .20) or brushed (P = .25) their hair. Hair pull test values were similar between Caucasian-, Asian-, and Afro-textured hair. There was no significant difference in hair pull values between participants taking medications affecting hair loss and participants not taking these medications (P = .33). Tight hairstyles did not influence hair pull test values. LIMITATIONS: Participant hair washing and brushing could not be controlled during the study, but this information was documented and analyzed. CONCLUSION: Normal values for the hair pull test should be reduced to 2 hairs or fewer (97.2% of participants). The current 5-day restriction on pretest hair washing can be reduced and brushing be made permissible.
BACKGROUND: The hair pull test lacks validation and has unclear pretest guidelines. OBJECTIVE: We sought to quantify normal hair pull test values and elucidate the effect of pretest hair washing and brushing. The impact of hair texture and lifestyle was also examined. METHODS:Participants (n = 181) completed a questionnaire recording demographics, medications, and hair health/history. A single hair pull test (scalp vertex) was performed. RESULTS: The mean number of hairs removed per pull was 0.44 (SD 0.75). There was no significant difference in the mean number of hairs removed regardless of when participants washed (P = .20) or brushed (P = .25) their hair. Hair pull test values were similar between Caucasian-, Asian-, and Afro-textured hair. There was no significant difference in hair pull values between participants taking medications affecting hair loss and participants not taking these medications (P = .33). Tight hairstyles did not influence hair pull test values. LIMITATIONS: Participanthair washing and brushing could not be controlled during the study, but this information was documented and analyzed. CONCLUSION: Normal values for the hair pull test should be reduced to 2 hairs or fewer (97.2% of participants). The current 5-day restriction on pretest hair washing can be reduced and brushing be made permissible.
Authors: George R Thompson; Charles R Krois; Verena K Affolter; Angela D Everett; E Katarina Varjonen; Victoria R Sharon; Anil Singapuri; Michael Dennis; Ian McHardy; Hong Sik Yoo; Dawn M Fedor; Nathan P Wiederhold; Phylicia A Aaron; Angie Gelli; Joseph L Napoli; Stephen D White Journal: Antimicrob Agents Chemother Date: 2019-01-29 Impact factor: 5.191