From the Guidelines
Head lice can be effectively treated using over-the-counter pediculicides containing permethrin 1% (like Nix) or pyrethrin with piperonyl butoxide (like RID), with a second treatment recommended 7-10 days later to kill newly hatched lice. The treatment should be applied to dry hair, left on for 10 minutes, then rinsed out 1. For resistant cases, prescription options include malathion 0.5% (Ovide), benzyl alcohol 5% (Ulesfia), or ivermectin 0.5% (Sklice) 1.
Some key points to consider when treating head lice include:
- Using a fine-toothed nit comb daily for at least two weeks to remove lice and eggs
- Washing all bedding, clothing, and personal items used in the past 48 hours in hot water (130°F) and drying on high heat
- Sealing non-washable items in plastic bags for two weeks
- Vacuuming furniture and floors where the infested person has been
- Checking and treating family members and close contacts if necessary to prevent reinfestation 1
It's also important to note that permethrin is a synthetic pyrethroid with extremely low mammalian toxicity, and is less allergenic than pyrethrins, making it a safe and effective treatment option 1. Additionally, ivermectin may be an effective treatment option, but its use should be cautious in young children due to the risk of adverse drug reactions 1.
Overall, the goal of treatment is to eliminate the head lice infestation and prevent reinfestation, while also minimizing the risk of adverse effects and promoting quality of life. The most effective treatment approach will depend on the individual case and may involve a combination of medication, combing, and environmental interventions.
From the Research
Head Lice Treatment Options
- Multiple therapies exist for the treatment of head lice, including topical pediculicides and oral medications 2
- Available over-the-counter and prescription treatments include pyrethroids, permethrin, lindane, malathion, ivermectin, and trimethoprim-sulfamethoxazole 2
- Dimeticone, a silicone compound, is a better choice for head lice treatment due to its few known adverse effects and proven efficacy 3
Efficacy of Different Treatments
- Pyrethroids, such as permethrin, have variable lice eradication rates ranging from 13% to 75% due to the development of resistance 3
- Malathion, an organophosphorus insecticide, has achieved eradication rates of 80% to 98% in randomised trials 3
- Topical application of ivermectin or spinosad was effective in 75% to 85% of patients in randomised trials 3, 4
- Spinosad has demonstrated superior performance compared to permethrin, with 84.6% and 86.7% of patients free of live lice 14 days after treatment 4, 5
Safety and Adverse Effects
- Insecticides have mainly local adverse effects, such as pruritus and irritation of the scalp 3
- Cases of malathion poisoning have been reported following topical application or ingestion 3
- Dimeticone has few known adverse effects and is not absorbed through the skin 3
- Spinosad has been shown to be well-tolerated, with mild to moderate adverse events, including eye irritation and application-site erythema/irritation 4, 5