Eyebrow growth pattern analysis in patients with eyebrow hypotrichosis after receiving topical treatment: A retrospective study

Background Differences in growth patterns among the various parts of the eyebrow have been observed. Aims We aimed to investigate changes in the hair density and diameter and analyze the eyebrow growth pattern of each eyebrow part (head, body, and tail) in patients with eyebrow hypotrichosis over a 24-week course of topical treatment. Patients/methods A retrospective study of 48 patients who received treatment with bimatoprost 0.01% was conducted. Patient demographic data were collected; measurements of hair density and diameter in the different parts of the eyebrow were collected and statistically evaluated. Results The tail of the eyebrow revealed the lowest baseline eyebrow density and diameter. Significant changes in eyebrow density (P = .01) and diameter (P = .01) were first detected in the tail at 4 and 16 weeks of treatment, respectively. The head and body showed a comparable growth pattern. Conclusions This study confirms the previous observations that hair density, diameter, pattern of growth, and hair growth cycle vary according to their anatomical location within the eyebrow. A better understanding of eyebrow growth pattern could provide the precise pathomechanism of eyebrow hypotrichosis leading to a standardized treatment protocol.