Diagnosis of a head lice infestation is best made looking for a live nymph or adult louse on the scalp or hair of a person suspected of the infestation. Because nymphs and adult lice are very small, move quickly, and avoid light, they can be difficult to find. A magnifying

Head Lice Diagnosis (CDC photo)

lens and a fine-toothed comb may be helpful to find live lice. If you are not able to find crawling lice, finding nits firmly attached within a 1/4 inch of base of the hair shafts strongly suggests, but does not confirm, that a person is infested and should be treated. Nits that are attached more than 1/4 inch from the base of the hair shaft are almost always dead or have already hatched. Nits are often confused with other things found in the hair such as dandruff, hair spray droplets, and dirt particles. If no live nymphs or adult lice are seen, and the only nits found are more than ¼-inch from the scalp, the infestation is probably old and no longer active and does not need to be treated.

If you are not sure if a person has head lice, contact your health care provider, local health department, or other person trained to identify live head lice.

To prevent head lice try Zippity Doo’s Lice Prevention hair care products.