Head Lice
Head lice are small parasitic insects that thrive in human hair by feeding on tiny amounts of blood from the scalp. An estimated six to 12 million infestations occur in the U.S. annually. It is particularly common among pre-school and elementary school children. Head lice do not transmit any diseases, but they are very contagious and can be very itchy. They are characterized by the combination of small red bumps and tiny white specks (also known as eggs or nits) on the bottom of hair closest to the skin (less than a quarter-inch from the scalp).
Head lice are visible to the naked eye. The eggs look like yellow, tan or brown dots on a hair. Live lice can also be seen crawling on the scalp. When eggs hatch, they become nymphs (baby lice). Nymphs grow to adult lice within one or two weeks of hatching. An adult louse is about the size of a sesame seed. Lice feed on blood from the scalp several times a day. They can also survive up to two days off of the scalp.
If your child still has head lice after two weeks with over-the-counter medicated products, contact your dermatologist for more effective treatment.