---Nit on a shaft of hair.
NEW ORLEANS - Many physicians are trying to deal with "head lice from hell" - infestations that are growing resistant to the normal pediculicides.
In some areas, the resistant problem is so bad that physicians are turning to unusual treatments, such as smearing the head with petroleum jelly, mayonnaise or olive oil. In each case, the patient's head is completely covered with the oil-based product and then covered with a shower cap. The child then goes to sleep, and the next day, the hair is shampooed.
"Lately, there have been reports of a number of treatments because there are resistant lice," said the late Milton Orkin, MD, who was clinical professor, University of Minnesota Hospital in Minneapolis. Orkin died shortly after the conference.
"The term is the head lice from hell. One cure is petroleum jelly with or without occlusion. You just gum up the hair completely with Vaseline and then you put a shower cap on and wear it to bed overnight. The theory behind this is that the side of the lice where the oxygen exchange takes place get plugged by the petroleum jelly. Those who use it are very enthusiastic about it."
Orkin, who spoke here at the 57th Annual Meeting of the American Academy of Dermatology, said he found a reference in the literature to the use of mayonnaise, but has never "prescribed this cure.
"It was very specific. You couldn't use lite and you couldn't use Miracle Whip, you had to use mayonnaise. I have no experience with it. And olive oil is on the same principle as with petroleum jelly."
These home remedies appear to work, and they don't do any harm, however physicians have complained that patients have a difficult time removing the greasy products from the hair and require frequent shampooing.
The medical treatments for resistant head lice are a short course of trimethoprim-sulfamethoxazole (TMP-SMX) or ivermectin (Merck), which is a product that has been prescribed for River Blindness.
Although there are some reports that TMP-SMX is not effective, Orkin said that he has used it on patients with recurrent or persistent head lice and it was effective. "I did give them TMP-SMX and it did work," he said.
"I would like to read you the description of this report in the British Journal of Dermatologyafter oral treatment of trimethoprim-sulfa. `Within eight to 24 hours of administration of trimethoprim-sulfa, there is intense itching of the scalp, and the lice can be seen crawling in these areas. in the next 12-48 hours, the lice migrated to the bedclothes and later died. During this period, the lice could be seen falling off the hair in a sluggish state.'"
For head lice treatment, TMP-SMX is dosed twice a day for three days, he said. Retreatment is necessary after seven days to kill any remaining active nits that hatched.
"If you use systemic therapy, you have to retreat after about seven days to get the eggs that might hatch," Orkin explained. TMP-SMX works by changing the bacteria in the gut of the louse, which prevents the louse from absorbing vitamins from the blood meal of its host. "The louse actually dies of a malabsorption vitamin-type deficiency. After a while, the louse starts laying infertile eggs. So, if you know the hatching time of the nits that have already been laid is seven days, and you treat for three days with TMP-SMX, seven days off, treat for another three days, you have caught the nits that have been hatched out before they can lay any fertile eggs," he said.
Ivermectin is an antiparasitic that is usually used for onchocercosis. It is also effective against head lice and scabies, Orkin said, and being prescribed more often for that purpose. Scabies and lice treatment, however, is an off-label use for ivermectin.
If you are going to use ivermectin be sure that the pharmacy has it because ivermectin is not carried by every American pharmacy, he warned. "The first time I used TMP-SMX was exactly in such a patient. The pharmacy called me and said we don't have any of this ivermectin stuff, and I said give them trimethoprim-sulfa and it worked."
The standard treatment for normal, run-of-the-mill head lice is permethrin or pyrethrum, which are both effective, he said.
Pyrethrum, which is a chrysanthemum-derived product, is sold as A 200 (Hogil), Peranade and Rid (Pfizer), does kill more rapidly than Lindane. These products kill about 68% to 77% of the nits. Pyrethrum is in the same category. Comparative studies have not been done, the assumption is permethrin and pyrethrum are equally efficacious, according to Orkin. Pyrethrum products include Nix (Warner Lambert), Pronto (Del) and Clear Total Lice (Care Technologies) and Elimite (Allergan), which is available by prescription.
"And Lindane is available and valuable for the treatment of pediculosis capitis," Orkin said. "As I recall, the shampoo has the same percent of lindane that's in the lotion itself and supposedly the kill time is five minutes. So, I've had patients use the shampoo and just leave it on. I would only treat the treatment failures with the lindane left over night."
Removing the nits can be a real pain, and most schools and day care centers have very demanding "no nit" policies, even if the physician says the white, sticky cement is nit-free. Administrators don't want to see any nits. "We are running into trouble in schools with the so-called stubborn nit or the zero tolerance of nits. I'm sure you've pulled off a couple of hairs off a child who was treated and came in complaining that they still had nits and you look at them under the microscope and they are little hallow nits. There is no movement, and yet, they are not allowed back in school," he explained.
Orkin used to recommend that parents soak the head with a diluted vinegar solution and then use a fine-toothed comb to remove the stubborn nits. Now, he recommends a product called Step 2, which is very good a removing nits.
The National Pediculosis Association also sells a very fine toothed comb that helps with nit removal. The association has a web site at http://www.headlice.org.
"Their information is patient oriented, very strong bias against any off-label uses of anything. For instance, they have nothing good to say about ivermectin," he said.
The Internet can be a hindrance in lice treatment, Orkin said. Many web sites criticize current lice treatments. Some want to sell "natural" products, Orkin said, but patients are turning to the Internet for information.
"One organization claims lindane is a not only a nerve poison but a known carcinogen," he said. The list of side effects was extreme. He said that many sites exaggerate the side effects and make false claims that are not based in scientific data. "And this is where your patients are getting their information!" he said.
"It is scary what patients can get on the Net," he added. "Your patients are able to go on the Internet and get something that absolutely magnifies the potential side effects and toxic effects of the medications you are giving them. It's okay for you to say to a patient, `You may find something on the Net that is insane about this medicine. We've been using this for 10 years and it is safe when used as directed. Don't believe what you see on the Net.'"
Orkin said that the University of Oregon had an excellent web site that provides good patient information. Go to the home page and it will direct the patient to the lice site. The homepage address is http://darkwing.uoregon.edu.
For more information:
- Orkin M. Scabies & pediculosis 1999. Session DSG442. Presented at the American Academy of Dermatology. March 19-24. New Orleans.
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