Immediate-Onset Linear Effluvium Associated With High-Density Hair Transplantation: A Series of 28 Cases.

We describe 28 patients who experienced effluvium with previously unreported features shortly after hair transplant surgery. Notable features were as follows: a) a linear morphology; b) immediate onset (1-3 days); c) association with dense-pack grafting in areas of receding hairline at the temples (Mickey Mouse pattern); d) a progressive increase in the diameter of the hair loss line (wave-like pattern); e) in some cases, subsequent concentric linear effluvium on the crown (donut pattern); and f) other forms of previously unreported immediate-onset effluvium. The linear morphology could be the result of dense packing, which can cause perilesional hypoxia and loss of miniaturized hairs around the recipient area.