New Head Lice Treatment is Nice and Easy
Head lice is a problem that can affect any child, regardless of economic or social class, and it continues to be a significant problem throughout the United States. Treating lice can be a challenge, but the results of two new Phase III studies indicate that treatment can be nice and easy, which could be a welcome option for parents of children affected by this pest.
Lice Are Not So Nice
Infestation with head lice is most commonly seen among preschool and elementary school children in the United States, according to the Centers for Disease Control and Prevention (CDC). It's been estimated that 6 to 12 million infestations with head lice occur each year in the United States among children ages 3 to 11 years.
Treatment of head lice can be problematic, especially since lice can be resistant to the traditional medications, and so the results of the new trials are of particular interest to parents and school officials. In the study, a drug called ivermectin (Sklice) was found to eliminate lice after just one application, and nit combing was not required.
Nits are lice eggs, and adult female lice lay the eggs at the base of hair shafts, where they attach to the hair. Because nits are extremely small and appear white or yellow, they can look like dandruff.
Typically, treatment of head lice involves applying medication to the scalp and hair and then using a nit comb to comb the hair thoroughly to remove nits and lice. Often the hair needs to be treated again, and combing should be repeated several times.
In the new studies, use of ivermectin lotion was compared with an inactive comparator. In both trials, which were completed by 765 individuals, the numbers of patients free of lice when compared with controls were as follows:
- One day after treatment, 94.9% vs 31.3% of controls
- One week after treatment, 85.2% vs 20.8%
- Two weeks after treatment, 73.8% vs 17.6%
According to William Ryan, BVSc, of Ryan Mitchell Associates, which sponsored the trials, and his colleagues, their results "indicate that ivermectin is a treatment option when permethrin or pyrethrins have failed or when there is a desire to reduce the need for nit combing and increase the probability of success with a single application."
More about ivermectin
The Food and Drug Administration (FDA) approved topical ivermectin 0.5% lotion (Sklice) in February 2012 for treatment of head lice in anyone ages 6 months and older. Ivermectin works by attaching to the nerve and muscle cells of lice, paralyzing and killing them.
In an accompanying editorial, Olivier Chosidow, MD, PhD, of the French National Institute of Health and Medical Research (INSERM), and Bruno Giraudeau, PhD, of INSERM, noted that while ivermectin lotion was "indeed welcome and is expected to have less risk of systemic adverse events," they also warned that it should not be the first treatment parents or physicians reach for when treating head lice.
"With good comparative-effectiveness research still lacking, indirect comparisons...support the 2010 American Academy of Pediatrics recommendations to use 1% permethrin or pyrethrin insecticide as first-line therapy," they explained. However, given the growing resistance to these first-line treatments, and sometimes to the second choice of malathion, ivermectin can be an effective option.
What you should know about head lice
There is a misconception that people get head lice because they are dirty or live in an unclean environment. In fact, the CDC notes that "personal hygiene or cleanliness in the home or school has nothing to do with getting head lice." Cats, dogs, and other pets also do not spread head lice.
Head lice spread by crawling--they cannot fly or hop. That means people usually share lice by direct contact, which may mean sleeping in the same bed at home or sharing nap time at daycare or during a sleepover. It is also possible, although less common, to spread head lice by sharing clothing if the lice or nits are attached to hair on the items, such as hats, towels, or scarves.
Although head lice do not spread disease, they are not nice: they are contagious and bite. Lice bites can cause children to scratch their scalp until it becomes inflamed and even infected, so it is important to treat head lice as soon as possible.
Chosidow O, Giraudeau B. Topical ivermectin--a step toward making head lice dead lice? New England Journal of Medicine 2012 Nov; 367(18): 1750-52
Pariser D et al. Topical 0.5% ivermectin lotion for treatment of head lice. New England Journal of Medicine 2012; 367(18):1687-93