Pseudopili annulati in a dark-haired individual: a light and electron microscopic study.

We report pseudopili annulati for the first time in a dark-haired Chinese girl. The hair was elliptical in shape and twisted along its long axis. The banded or ringed appearance was due to incident light being reflected by the flattened segments. Banding was also noted under polarized light but was not present under transmitted light. Under transmitted light the whole length of the hair appeared dark and the thickness varied at regular intervals, giving rise to fusiform segments due to the twisted nature of the hair shaft. Scanning and transmission electron microscopic examinations revealed no abnormalities in the cuticle and cortex.