From the Guidelines
Head lice can be effectively treated with over-the-counter or prescription medications, and the most recommended initial treatment is permethrin 1% (Nix) or pyrethrin-based products (RID, A-200) applied to dry hair, left on for 10 minutes, then rinsed out, as stated in the study by 1. The treatment of head lice should prioritize effectiveness, safety, and ease of use.
- Permethrin 1% is a recommended treatment due to its low mammalian toxicity and low risk of allergic reactions, as noted in the study by 1.
- Pyrethrin-based products are also effective, but may cause allergic reactions in individuals with plant allergies, as mentioned in the study by 1.
- For resistant cases, prescription options include malathion 0.5% (Ovide), benzyl alcohol 5% (Ulesfia), spinosad 0.9% (Natroba), or ivermectin 0.5% (Sklice), as stated in the study by 1.
- It is essential to follow complete treatment protocols, including a second treatment 7-10 days later to kill newly hatched lice, and to use a fine-toothed nit comb daily for 2-3 weeks to remove dead lice and nits, as recommended in the study by 1.
- Additionally, washing bedding, clothing, and personal items used within 48 hours in hot water (130°F) and drying on high heat can help prevent re-infestation, as suggested in the study by 1.
- Family members and close contacts should be examined and treated if infested, as head lice cannot survive long without a human host and do not indicate poor hygiene, as stated in the study by 1.
- Resistance to traditional treatments has increased, so it is crucial to follow complete treatment protocols and consider alternative treatments if necessary, as noted in the study by 1.
From the FDA Drug Label
Malathion lotion is indicated for patients infected with Pediculus humanus capitis (head lice and their ova) of the scalp hair. Apply malathion lotion on DRY hair in amount just sufficient to thoroughly wet the hair and scalp. Pay particular attention to the back of the head and neck while applying malathion lotion. After 8 to 12 hours, the hair should be shampooed. Rinse and use a fine - toothed (nit) comb to remove dead lice and eggs. If lice are still present after 7 - 9 days, repeat with a second application of malathion lotion.
Treatment of head lice with malathion lotion involves applying the lotion to dry hair, allowing it to dry naturally, and then shampooing after 8 to 12 hours. A second application may be necessary if lice are still present after 7 to 9 days 2, 2.
- Key steps:
- Apply malathion lotion to dry hair
- Allow hair to dry naturally
- Shampoo after 8 to 12 hours
- Repeat application if necessary after 7 to 9 days
From the Research
Treatment Options for Head Lice
- Various therapies are available for the treatment of head lice infestation, including over-the-counter and prescription formulations 3
- Treatment options include pyrethrin, permethrin, malathion, ivermectin, and alternative therapies such as dimeticone 3, 4, 5
- Malathion is considered a second-line therapy due to its flammability, but it has been shown to be effective in eradicating head lice infestation 3, 6
- Orally administered ivermectin has been reported to be efficacious, but it is not currently a US Food and Drug Administration-approved pediculicide 3, 6
Efficacy of Treatment Options
- A study comparing oral ivermectin with 0.5% malathion lotion found that ivermectin had superior efficacy in eradicating head lice infestation 6
- Dimeticone, a silicone compound, has been shown to be effective in eradicating head lice infestation with few known adverse effects 5
- Pyrethroids, such as permethrin and phenothrin, have been found to have variable efficacy in eradicating head lice infestation, likely due to the development of resistance 5
Safety and Adverse Effects
- Insecticides, such as malathion and pyrethroids, have mainly local adverse effects, including pruritus and irritation of the scalp 5
- Cases of malathion poisoning have been reported following topical application or ingestion 5
- Dimeticone has been found to have few known adverse effects and is considered a safer alternative to insecticides 5