Pediculosis is the infestation of blood sucking lice and is characterized by severe itching. Only humans transmit lice from one to another.

The symptoms are disturbing. The raised papule areas on the skin itch severely. With constant scratching, secondary bacterial infections may occur (such as impetigo or boils). Neither head lice nor pubic lice transmit infections directly, but severe scratching will. Dirt and bacteria under the fingernails transmit infections during scratching.

The first step to distinguish between head and pubic lice is the area of infestation. Head lice are usually found on the nape of the neck and behind the ears. Examination of these areas shows small, grayish-white eggs (nits). The nits may be mistaken for dandruff, but cannot be easily brushed away. Pubic lice are not always confined to the crotch or perianal area, but may attach to any hairy area of the body.

Head Lice - Millions of American children become infested with head lice each year, regardless of cleanliness. Head lice do not discriminate and can live in the scalp and hair of all children (and parents and other caregivers, should the infestation spread at home) regardless of sex, race, cleanliness or economic status. Lice are most often found on school-age children, particularly those in lower grades. Girls have higher incidence of lice than boys, while African-American children have a much lower incidence of infestation that Caucasian, Asian, or Hispanic children.

Infestation begins through direct, head-to-head contact with infested persons, by wearing infested clothing, using infested combs or hairbrushes, or lying on infested bedding, carpeting, or furniture. Some of the specific paths of contagion are children swapping hats or borrowing scarves; clothing hung close together in school coatrooms or using other's combs or brushes. Other areas of transmission may be from bed linen, sleeping bags, headphones, and the headrests of chairs or couches.

The head louse is tiny, moves quickly through the hair and is difficult to see. A lice infestation is usually confirmed by finding nits, which are yellowish-white oval specks, attached to the hairs, generally near the scalp. In warmer climates, nits may be found several inches from the scalp.

Pubic Lice - Pubic lice are most frequently spread by sexual contact, by bedding and shared clothing and towels. Even toilet seats can spread pubic lice because the creatures can live 24-48 hours off the host.

Body Lice - Body lice are extremely rare in the U.S. and require medical supervision and diagnosis.

The head louse is a human parasite and cannot live on the body of a dog or cat.