Patients with a Chrysanthemum allergy may also be allergic to permethrin. Contact with the eyes or mucous membranes should be avoided. Resistance to permethrin is emerging(11).

OTHER INTERVENTIONS
The growing resistance of head lice to synergized pyrethrins and permethrin have caused many consumers to turn to alternative methods of treating head lice. Some are ineffective and dangerous, but diligent combing is rapidly emerging as the treatment method of choice.

Hair Removal. The pharmacist should advise against shaving the head of the individual infested with head lice. While it is undeniably effective, the child may become the focus of teasing among classmates.

Flammable Chemicals. Unfortunately, reports of death and injury continue to accumulate when individuals use flammable chemicals to treat head lice. Reports of these accidents are usually confined to newspapers and news media in the state where the accident occurred, which does not allow one to gain a handle on the national scope of the problem. Nevertheless, it is a growing phenomenon. In Oklahoma, a man rubbed gasoline on his daughter's hair. It ignited, causing second-degree burns to the father(12). Gasoline use on head lice also caused an Oklahoma house fire which killed a baby. A 16-year-old girl using gasoline experienced 2nd and 3rd degree burns over 90 percent of her body when a pilot light on a water heater ignited the fumes(13). Another family used lantern oil, which ignited, causing third-degree burns over 50 percent of the eight-year old child's body and third-degree burns on the mother(14). Similar fires have occurred with kerosene and other flammables. In all probability, patients using old home remedies such as these have not sought the advice of a pharmacist, perhaps due to embarrassment. For this reason, the pharmacist must highlight the dangers of these and similar home remedies whenever the opportunity arises, such as any public health speaking engagement.

Dangerous Pesticides. Some people resort to dangerous pesticides which are not meant to be used on humans. For instance, some nonprescription veterinary flea preparations may list lice on the label. People assume that they are safe for human lice, using them indiscriminately on children and adults. Their toxicity is unknown and their effectiveness for human lice is questionable. They must be avoided.

Even worse, some patients resort to highly concentrated pesticides. In an Oklahoma case, a six-year-old child with head lice was treated with industrial strength diazinon(15-17). Within 15 minutes, her respiration ceased and she suffered full cardiac arrest. After almost three weeks in a hospital, she was evaluated as having permanent brain damage. Charges of child abuse were filed against the mother's boy friend who treated the child, with bail being set at $100,000. Eventually, the charges were dismissed, but the prosecutor appealed that decision. Pharmacists must strongly advise against any unapproved pesticide in humans.

Alternative Treatments. Several companies have begun promoting wholly unproven head lice remedies. They include tea tree oil, rue and other herbal ingredients. These herbs suffer from a twofold problem: lack of information about safety and absolutely unproven efficacy. Patients using them suffer from a false sense of security that they are actually treating the problem. This allows the head louse population to increase unchecked, worsening the infestation and associated symptoms. Pharmacists must advise against these natural herbal interventions until sufficient data proving safety and efficacy is submitted to the FDA.

Suffocating Treatments. Some patients turn to friends and Internet sources, who have heard of suffocating head lice by applying heavy oil-based products to the head for varying lengths of time. As an example, patients are advised to cover the hair with mayonnaise or olive oil and wrap the head in plastic wrap, leaving it on overnight. There are several problems with this approach. The efficacy of suffocating agents is unproven, as there are no studies comparing them to other remedies(18). The products must eventually be removed from hair, and the heavy load of oil on the hair may require multiple shampooing with harsh detergents. The net effect is irritation of the scalp. Of course, the potential hazards of sleeping all night with one's head covered in decomposing mayonnaise or rancid olive oil are also vitally important. If one has open wounds on the scalp, as many longstanding head lice sufferers do, bacterial contamination of the mayonnaise or olive oil could cause a skin infection. Pharmacists should advise against unproven therapies such as oily suffocating agents.

Nit Cement Dissolving Agents. An old home remedy is to use acidic products to dissolve the cement holding the nit to the hair shaft. However, when patients have used acidic products such as vinegar, they have caused facial and ophthalmic burns(19). Use of vinegar should be discouraged.

Several commercial products which allege to dissolve the nit cement have been marketed. Step 2 employs formic acid, but its efficacy is unproven. Clear claims that its enzyme-based approach dissolves the cement, but the manufacturer was cited by the Federal Trade Commission for falsely claiming that the efficacy was proven by laboratory and field studies(9).

Household and Environmental Sprays. Several companies have marketed aerosol sprays which patients can use to spray the environment. However, the use of these products should be discouraged for several reasons. When a household member has head lice, the major reservoir is the heads of the victims. Few lice are found out in the surrounding environment, unless they have been accidentally dislodged from the head during acts such as scratching or combing. Another problem with environmental sprays is that they foster the paranoia of affected family members, who tend to overuse them, spraying all household surfaces. Since these are pesticides, their safety upon inhalation over a sustained period is unproven. One can only imagine the toxicological effect of the pesticide on a sleeping child lying face down on a heavily sprayed mattress and pillow over a 10-hour sleep cycle. The safest and most effective alternatives the pharmacist should recommend for environmental lice removal is reassurance coupled with thorough vacuuming of the environment.

THOROUGH COMBING AS THE EMERGING TREATMENT OF CHOICE
The various pesticides marketed for control of head lice are toxic to the patient in varying degrees and lead to the development of resistance. Other treatments are of unknown safety and/or efficacy, and some are highly dangerous. For these reasons, pharmacist recommendations should shift in the new millennium to thorough combing with a highly effective comb such as the LiceMeister^�, which has been registered with the FDA as a medical device(5). Its use was described above as a tool to confirm an infestation. However, it also treats the infestation by removing the nits. Resistance and toxicity are non issues with this mechanical lice removal aid.

SUMMARY
Students in their senior year realize that the real world is uncomfortably close. They appreciate learning about nonprescription products from a faculty member who is a registered pharmacist and who also continually works in a retail pharmacy. This ongoing practice paid off handsomely in the area of head lice treatment by allowing me to gain an early appreciation for the emerging problem of resistance, as evidenced by the large numbers of people with whom I consulted and for whom traditional nonprescription products were ineffective. It also allowed me to recommend an improved way to eradicate head lice, and to monitor patients who purchased it. Describing these actual work situations to students enriches the academic experience and helps students bring the most effective treatments to their patients when they enter their own practice settings.

Am. J. Pharm. Educ., 63, summer 1999

DCDays.com would like to thank the American Journal of Pharmaceutical Education - 8/4/99.