Friday, November 2, 2012

New treatments for head lice

- Kenny Lin, MD

Pediculosis is a distressing diagnosis that frequently causes children to be sent home from school or day care. In the September 15th issue of American Family Physician, Dr. Karen Gunning and colleagues provided a treatment update for pediculosis and scabies. Permethrin 1% lotion or shampoo is the recommended first-line treatment for head lice infestation (see illustration below). However, permethrin resistance is increasingly common in many communities, and second-line therapies have substantial disadvantages: malathion is flammable, and lindane is neurotoxic and cannot be used in young children. Additional safe, effective treatments are now being developed.

Yesterday, researchers reported in the New England Journal of Medicine the results of two randomized trials evaluating a single 10-minute home application of topical 0.5% ivermectin lotion for head lice in patients 6 months of age or older. Compared to the control groups, patient assigned to receive ivermectin were significantly more likely to be louse-free at day 2 (95% vs. 31%) and day 15 (74% vs. 18%), with no difference in adverse events. A major limitation of these studies is that topical ivermectin was compared to a placebo rather than to established head lice treatments.