An outbreak of the ectoparasite lice is called pediculosis. The best methods for head lice removal are the pediculicides malathion, lindane, or permethrin, or a benzyl alcohol lotion can also be used. These chemicals are highly effective for head lice removal, but they are very harsh and should be used exactly as directed, never ingested, and always discussed with a pediatrician before used on a child. Nits mature in seven to twelve days, so as a precaution each method should be repeated seven to nine days after the first treatment to be certain all lice has been irradicated.
The form of the pesticide malathion used for head lice removal is called Ovide®, a good pediculicide choice because human toxicity to malathion is fairly low and lice are not predominantly resistant to this chemical. This prescription lice treatment comes as a lotion which is worked through dry hair until it is saturated. The hair is then allowed to air dry for about ten hours, and should not be exposed to a hair dryer or placed near a heat source, since the lotion contains alcohol and is flammable. After ten hours, the hair is shampooed and a nit comb, a special, fine-toothed, egg-removing comb, is used to extract the dead nits and adult lice from the hair.
The procedure for head lice removal is about the same for the prescription shampoos, Kwell®, which contains the chemical lindane, and Nix®, which is the prescription shampoo form of permethrin, but the two shampoos should not be used together. Using rubber gloves, the shampoo is worked into dry hair. If using Kwell®, it is left on the hair for 4 minutes and if using Nix®, it is left on for about 10 minutes. When the setting time has passed, water is carefully added to the hair, worked into lather and then the shampoo is rinsed away, being careful to keep the rinsed shampoo from running over the body. The hair is then dried with a clean towel, a nit comb is used to remove the dead nits and lice, and the bathing area should be carefully cleaned to be sure none of the shampoo is left behind and inadvertently touched.
Ulesfia® is a lotion containing 5% benzyl alcohol and is a non-pediculicide treatment for head lice removal, killing the lice and nits by suffocation. This lotion is applied liberally all over dry hair, being sure to saturate the head and immerse the lice and nits in the lotion. The lotion is left on for 10 minutes, and then the hair is shampooed and combed with a nit comb.