DEAR MAYO CLINIC: My child’s school has had a lice outbreak for two months. The problem does not seem to be going away. Is it true that some types of lice are resistant to over-the-counter treatments? Are there more potent options to eliminate head lice?
ANSWER: Although they are often effective, over-the-counter treatments for head lice don’t work in all cases. Some strains of lice can be resistant to the over-the-counter treatments. If head lice persist despite treatment at home, then it’s time to ask your doctor about prescription medication alternatives.
Head lice are tiny, wingless, parasitic insects that live and feed on blood from a person’s scalp. Head lice cause a lot of fear, anxiety and concern. Fortunately, although they are a nuisance, head lice don’t carry any transmissible diseases that are dangerous.
Head lice can spread easily. They may go from one person to another through direct contact, or they may be passed through shared items, such as combs, brushes and towels. Head lice tend to stay within about an inch of the scalp, anchoring onto a hair shaft. If you suspect that you or a family member has head lice, the best places to look are behind the ears and along the back of the neck, near the scalp. Lice are very small, about the size of a strawberry seed. Their eggs, or nits, resemble tiny pussy willow buds. Nits can be mistaken for dandruff, but they can’t be easily brushed out of hair.