All About Lice

Myth Fact All children with lice scratch or itch. Initial infestation may produce no signs or symptoms for 4 - 6 weeks. Lice jump or fly from head to head. Lice can be dislodged from hair by air movements giving the appearance of flying. Lice live in carpets, beds, clothes, and sofas Lice can only live for 24-48 hours away from a human host. Lice die immediately after treatment. Lice may take several hours to die following treatment. One treatment is enough. Due to loss of residual activity of pediculicides, two treatments are recommended to kill newly hatched nymphs. Permethrin based products are 100% ovicidal. Permethrin kills 70% of eggs with one treatment. Everyone in the family should be treated. Only those with a proven infestation should be treated, although everyone should be checked daily to weekly. Head lice prefer long or dirty hair. The likelihood of infestation is not affected by hair length or cleanliness. Table 2. Treatment Categories for Lice Therapies Standard pediculicides • Historically considered standard treatment; however instance of resistance have made it necessary to explore new alternatives• Not recommended for children <2 yrs• Apply to entire scalp Permethrin Nix® Permethrin-based RID®, R&C ®, Pronto®, A-200®, Kwellada-P®, Clear Lice System® Malathion Ovide® Lindane Kildane®, Kwell®, Scabene® Oral agents •Off-label use Ivermectin Stromectol® Trimethoprim/ Sulfamethoxazole Bactrim®, Septra® Non-neurotoxic pediculicides • Exoskeleton integrity dehydration pediculicide• Recently approved by Health Canada Isopropyl myristate 50% and ST-cyclomethicone 50% and ST-cyclomethicone 50% Resultz™ • Dry-on suffocation-based pediculicide Active agent unclear Nuvo® Method = Cetaphil® Cleanser Mechanical removal • Only treatment recommended for children <2 years n/a n/a Environmental intervention • Important to prevent recurrence n/a n/a Alternative treatments • Published data is sparse • Caution should be advised until more data is available. n/a n/a