The most obvious sign of head lice is an extremely itchy head, though other things (like dandruff) can make the scalp itch. But you can have lice and not be itchy. It sometimes takes a few weeks after the lice have arrived for the scalp to start itching. The itch is caused by the female louse biting the scalp.
If you are concerned about lice, you need to look carefully for them. The best way to do it is:
Adult lice are light brown and about the size of sesame seeds. You are more likely to see the eggs – called nits – than live lice. The nits:
Kids – and adults – can have all kinds of stuff in their hair, like sand, dirt, lint and dandruff, but those will comb out easily. Nits are cemented to the hair and very difficult to remove. You are most likely to find lice and nits in the hair behind the ears and around the nape of the neck.
Body lice look similar to head lice tend to live and lay eggs in clothing seams, leaving the clothing only to feed.
Also called crabs, pubic lice are smaller and rounder, and are more common in adults. They usually are found in pubic hair, but sometimes are found on other coarse hair on the body, such as the eyebrows.
Next: Treating Lice
Photo references:
Magnified adult head louse, magnified nit, and magnified adult body louse: These photos were previously published in Dermatology DDxDeck, Vol 1, Pg 93. Habif T. Campbell J, Chapman M et al. “Head lice (pediculosis).” Copyright Elsevier (2006).
Pubic lice (crab louse): These photos were previously published in Dermatology DDxDeck, Vol 1, Pg 57. Habif T. Campbell J, Chapman M et al. “Pubic lice.” Copyright Elsevier (2006).
