Head lice have likely plagued humans for as long as we’ve existed. They couldn’t survive on animals, preferring to stay in human hair, feed from the scalp, and attach their eggs (nits) to hair strands. Since lice can’t jump or fly, close physical contact facilitated their movement from one host to another-often hitching a ride on hats, bedding, or personal items stored together. Unfortunately, doctors and scientists of the time knew little about lice’s life cycle or source. Not until 1864 did Louis Pasteur definitively document it. To manage outbreaks, people used fine-tooth combs like those found in archeological digs to remove adult lice and nits from their hair.

Other treatments for head lice have evolved significantly over the centuries (and Fort Crawford). The use of sulfur and lard, as well as mercuric oxide powder, are historical methods that are no longer in use today due to their potential harmful effects. Mercuric oxide powder, also known as “red precipitate,” was also used in the past to treat various ailments, including lice infestations. Mercury compounds were common in the early 19th century for various applications, including medical treatments. However, the toxic properties of mercury were not fully understood at the time, resulting in significant health risks for those who were exposed to it. By the late 19th and early 20th centuries, the harmful effects of mercury were becoming more widely recognized, leading to a decline in its use in medical treatments.

While lice infestations are less common today, they still occur, and are spread in institutional settings, primarily such as pre-and-elementary schools, and to a lesser degree summer camps, sports teams. From understanding the life cycle of lice to recognizing the early signs of an infestation, information available today provides a wealth of information for parents, teachers, and caregivers in a position to monitor those most at risk. This body of information also addresses preventive measures, effective treatments, and the role of schools and childcare centers in managing outbreaks.