MARINA DEL REY, Calif. - Head lice continue to be a problem in the United States, affecting up to 25% of school-age children, and resistance to commonly used treatments is making physicians examine other options.
"This is not an uncommon disease," said Sheila Fallon Friedlander, MD, associate professor of pediatrics and medicine at the University of California and Children's Hospital, San Diego. "That's one thing you want to make clear to your patients when they walk in. Day care centers clearly have made it easier for these bugs to get from head to head."
Besides intense itching, enlarged lymph nodes in the cervical and occipital areas are often present. The patient may have a papular red rash on the temples and neck that is often mistaken for eczema, said Friedlander, who spoke here at the Second Annual Infectious Diseases in Children Symposium West. "Sometimes you will only see papules at the edge of the hairline, maybe some complaints of itching at the scalp line. When you hear that, look for nits. Look for nits close to the scalp. Live nits are slightly tan in color, and not so opalescent as empty nit casings. If there's a doubt in your mind, you can cut the hair off and look at it under a microscope."
Several treatment options are available, but none is 100% effective, Friedlander said. "No matter what you give families, they have to spend some time removing nits. You have to teach them to nit pick."
Permethrin creme rinse (Nix, Warner-Lambert) remains standard treatment for head lice "For families, the first time a child has an infestation, you use Nix," Friedlander said. "It's perfectly OK to start with this treatment in a fresh case. We have a lot of experience with it. In many cases it will be effective. It's safe, it's rapidly metabolized, and it's not extremely expensive."
The problem with permethrin, however, is that head lice are becoming resistant. Anecdotal reports of resistance have been reported since 1986 in Israel, Great Britain and Czechoslovakia. Recent studies indicate that it is a growing problem in the United States as well.
Permethrin cream 5% (Elimite, Allergan) is generally the next treatment option when lice persist despite treatment. Families should put it on dry hair and leave it on overnight and repeat 10 days later.
"I don't keep doing that with a family," Friedlander said. "But in the vast majority of cases, that solves the problem, along with looking at other family members."
Malathion (Ovide, Medicis) is also proving to be quite effective. One study showed it to be 95% effective with just one treatment, Friedlander said. Odor and flammability are problems, however. "You've got to keep the kids away from open flames and hair dryers," she said. "On the other hand, some of you may have very anxious families who want to do anything to get rid of the bug. It's a very effective agent." Malathion should not be used in neonates or infants.
Two oral agents are available for treatment of head lice. "The new great hope for both lice and scabies is ivermectin (Stromectol, Merck)," Friedlander said. "All the studies have shown that this drug is quite efficacious for lice, but not 100%. You need to repeat treatment seven to 10 days after your first treatment."
Caution should be exercised when using ivermectin in children, Friedlander said. "Don't use repeated doses."
Dosing should be at least 200 mg/kg, Friedlander said. "Less than 200 mg/kg is not good for scabies and appears not to be that good for head lice. Some studies show that higher doses work better, and repeat doses give you better efficacy. Again in younger kids, I'm not going to go higher than 200 mg nor will I do multiple treatments until there's more experience with this drug."
Trimethoprim-sulfamethoxazole (TMP-SMX) can be given for three days and repeated in 10 days or as a full seven-day course.
"Some people like oral TMP-SMX," Friedlander said. "I see lots of drug reactions from TMP-SMX. In my experience, it is the number one antibiotic to cause drug reactions, so I don't tend to use that. However, some people do."
Several treatment options do not require medication. "Bug busting" is the treatment of choice in the United Kingdom and consists of using a fine-toothed comb to remove nits and bugs from the head. This should be done with wet, conditioned hair and may be done in combination with other treatments.
Household agents "that are messy but harmless" are another option for families resistant to medications, Friedlander said. For example, petroleum jelly is very effective at removing head lice by suffocating the organism.
The problem with petroleum jelly is removing it, Friedlander said. "The next morning they're going to have to wash it out with a grease-cutting detergent," she said. "Some people say that if you sprinkle baby powder over the petroleum jelly covered hair and comb it out it's easier to remove some of the petroleum jelly, but that's a tough job."
Full-fat mayonnaise, olive oil or Dippity-Do brand styling gel may be helpful as well, Friedlander said.
Hair Clear 1-2-3, which consists of coconut oil, ylang ylang oil and anise oil, is available in health care stores and is also reported to work well. "When you apply it, apparently the bugs jump off of the head," Friedlander said. "They really dislike this. For your homeopathic families, you've made their day. You did not give them any dreaded drugs."
Once a treatment option has been established, ensuring outside factors are controlled is vital.
"You need to think about the environment and family," Friedlander said. "Often times, you'll be confronted with a case where they've done the right things, and they're still infected. You need to make sure they understand how to physically remove the nits. You need to look at brothers and sisters; you need to think about day care. Maybe that child is lying on the floor at day care and being reinfected by his buddy who hasn't been treated, yet."
Washing items in hot soapy water and drying them in a hot dryer will also help keep children from being reinfested. Non-washables should be dry cleaned or put in a plastic bag for two weeks or frozen for 48 hours. Cleaning headgear is also important, Friedlander said.
Five Treatment Options For Resistant Lice
1. Increase concentration of permethrin
2. Bug Busting
3. Physical Agents
4. New Topical Agents
5. New Oral Agents
For more information:
- Friedlander SF. What's new in cutaneous infection? Presented at the Second Annual Infectious Diseases in Children Symposium West. Feb. 26-27, 2000. Marina del Rey, Calif.
- Pollack RJ et al. Differential permethrin susceptibility of head lice sampled in the United States and Borneo. Arch Ped Adolesc Med. 999;153:969-973.
- Meinking JL et al. Update on the treatment of scabies and head lice. In: James WD, Cockerel DJ, Dzubow LM et al, eds. Advances of Dermatology. St. Louis, MO: Mosby-Yearbook Inc. 1999:15:1-42.
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