Pediculosis, or infestation with the human head louse (pediculus humanus capitis), is one of the most common human parasitic infestations worldwide. 1 In the United States, an estimated 6-12 million people are treated for head lice each year, and studies have shown that it’s most common among preschool and school-aged children. 2 Head lice can infest anyone’s hair, regardless of gender, nationality, race, or hygiene. Even the cleanest classrooms and tidiest households can be invaded by this common nuisance. The CDC provides helpful information regarding transmission and risk factors here.
You can help protect your family and educate your children by understanding more about the behavior of head lice and best practices for avoiding them.
- Head lice are parasitic insects that only attack humans. You won’t catch lice from the family pet, nor will you give lice to them.
- The most common way they spread is through direct head-to-head contact with an infested person. They can’t fly or jump.
- Head lice are very small — about the size of a sesame seed. They can be tan, brown, or gray in color.
- This parasite prefers a dark, warm environment and is often discovered behind the ears, under a ponytail and at the nape of the neck. They can also be found on eyebrows and eyelashes.
- Head lice stay alive by feeding on blood from the human scalp. They will die within 1 to 2 days after being off their host because they no longer have a food source.
- A female louse can lay up to 10 eggs daily; they prefer to lay their eggs ¼” from the scalp.
- At first glance, head lice eggs (or nits) might be mistaken for dandruff. But they are firmly attached to the hair shaft with a waterproof glue-like substance and won’t brush off.
- Anyone can get head lice. They know no socioeconomic or ethnic boundaries, and are equal opportunity infesters.
- Males are less likely to get head lice than females because they typically have shorter hair.
- Lee, S.H., Yoon, K.S., Williamson, M.S., Goodson, S.J., Takano-Lee, M., Edman, J.D., Devonshire, A.L., Clark, J.M. (2000) Molecular analysis of kdr-like resistance in permethrin-resistant strains of head lice, Pediculus capitis. Pest. Biochem. Physiol. 66: 130-143 ↩
- Centers for Disease Control and Prevention, Parasites – Lice – Head Lice, Epidemiology & Risk Factors, http://www.cdc.gov/parasites/lice/head/epi.html ↩