A brief history of lice

Louse: a type of small insect that lives on the bodies of people or animals; a bad or cruel person (Merriam-Webster)
Head lice have been around for a long time. Genetic studies suggest that lice developed about 1.68 million years before homo sapiens emerged, and that they started their relationships with humans about the same time human evolution separated from chimpanzee evolution. The oldest physical evidence of head lice on a human was a nit found on the hair of a 10,000-year-old body at an archeological site in Brazil.

Lice combs have been found in the tombs of Egyptian royalty, and even Cleopatra was said to have solid gold lice combs buried with her. Clearly, in those times, it was not considered a social blemish to deal with head lice. They wanted to have their lice combs in the next world. Even more surprising, perhaps, is that the technology for treating head lice did not change much for thousands of years. More on that later.

Intact nits have been found on the heads of the mummified remains of ancient Romans and Egyptians, and have vexed doctors and philosophers from Aristotle to Louis Pasteur. In 1100 A.D. a Rabbi proclaimed that it was permissible to remove head lice on the Sabbath. The war on lice has been going on for thousands of years, with little innovation to make it easier and more efficient.

The first recorded treatment of head lice comes from an Egyptian medical guide called the Ebers Papyrus dated around 1550 B.C. It recommends filling one’s mouth with warm date meal and water and then spitting it on the skin “in order to drive away the Fleas and Lice which disport themselves…” Science? Probably not. In China, documents from 1200 B.C. indicate they used mercury and arsenic compounds to drive away head lice. It didn’t work. By 450 B.C., Egyptians recommended shaving the entire body to eradicate lice, which, while effective, has proved impractical in the succeeding centuries.

In 100 A.D., the Chinese discovered that Pyrethrum powder, extracted from a species of chrysanthemum, was an effective insecticide. Marco Polo brought Pyrethrum powder to Europe in 1300 A.D., proclaiming it to be a near magical compound. Pyrethrin, a more refined extract of pyrethrum, was first available as a head lice treatment in the 1940s, and was indeed effective at killing head lice (though less effective at killing eggs, or nits). In 1977, Permethrin, a synthetic version of Pyrethrin, was introduced as a head-lice treatment product. By 1999, studies in Britain, Australia and the United States found head-lice strains were developing resistance to these natural and synthetic pesticides (collectively called Pyrethroids). In the United States, 80 percent of over-the-counter lice products contain Permethrin or Pyrethrin.

In addition to diminished effectiveness, these insecticide-based treatments involve a lengthy, painstaking process of applying the topical chemicals, combing out dead lice and eggs, and repeating the combing process for weeks to ensure that all of the eggs have been removed. It takes about 7-10 days for eggs to hatch. If a few eggs were missed and more lice are found after the application and combing, it’s time to start over. The stress and uncertainty surrounding whether a treatment has been effective is typically protracted because success is by no means assured.

While head lice have afflicted humans for millennia, it wasn’t until the poet Robert Burns wrote “To a Louse: On Seeing One on a Lady’s Bonnet at Church,” that we see head lice publicly stigmatized. In the poem, Burns excoriates the, “ugly, creeping, blasted wonder, detested, shunned by saint and sinner.” He goes on to say, “How dare you set your foot upon her – Such fine a lady … Go somewhere else and seek your dinner on some poor body. Off! In some beggar’s temples squat: There you may creep, and sprawl, and scramble.”

The head louse and lice outbreaks have snuck into our cultural literacy in ways that have confirmed Burns’ social verdict. The “louse,” as seen in the dictionary definition above, is synonymous with bad and cruel behavior. “Lousy” is defined as “very poor or bad, disgusting.” A nitwit is someone or something stupid, and a nitpicker is someone who is overly critical. And remember, every time you decide to go through something “with a fine toothed comb,” you are referring back to the most ancient of head-lice treatments.

Still, there are 6-12 million cases of head lice in the United States each year, according to the Centers for Disease Control and Prevention. Reporting of incidents tends to be erratic, with many parents hiding the condition from even their doctors, and others reporting anonymously through schools and day care centers. As a result, reliable data can be difficult to obtain. With lice developing resistance to insecticide-based treatments, research into topical cures has been slowed by a cloud of futility—head lice are evolutionary survivors and any new chemical cure could be relatively short-lived.

Thankfully, alternatives have been pursued, with recent success. In 2006, Larada Sciences, a U.S. medical-device manufacturer, developed AirAllé, the first FDA-cleared medical device clinically proven to kill not only head lice but 99.2 percent of lice eggs in children and adults. The device uses carefully controlled heated air to dehydrate head lice and eggs in a one-hour treatment in a medical clinic. Lice Clinics of America is proud to be the exclusive provider of the AirAllé head-lice treatment, and is rapidly adding new clinics throughout the world in response to growing demand.

Head lice are tenacious and tedious parasites, but they are not dangerous to human health and they are not related in any way to human hygiene. In fact, they are far more prolific on clean hair and scalps, because they have little resistance when follicles and skin are easily accessible. The fact that head lice are medically harmless doesn’t mean they are benign, as they can cause a great deal of discomfort and they can easily spread throughout a family or school.