Wet combing or dimeticone may be used to treat head lice in breastfeeding mothers. Malathion may be used as an alternative if a traditional insecticide is required in the case of treatment failure.
No studies on the passage of any of the parasiticidal agents used to treat head lice into human breast milk following topical application have been located.
Wet combing has achieved cure rates of up to 57% after 14 days. It is very time consuming, but may be preferred by people wishing to avoid using chemicals.
Dimeticone has a physical action, coating the lice and disrupting their ability to manage water. There is very little or no absorption of dimeticone through the skin.
Absorption of malathion through the skin is low, which one study showed was insufficient to have any systemic effect.
Theoretical considerations would indicate that the amount of malathion passing into milk after topical application would be too low to present a hazard to the breastfeeding infant.
Other preparations (isopropyl myristate/cyclomethicone or isopropyl myristate/isopropyl alcohol) are not contra-indicated during breastfeeding, but use should be with caution and only after other treatment options have failed.