Head Lice:

Alternative names:

lice - head; nits; pediculosis; pediculosis capitis

Definition:

Tiny parasitic insects (Pediculus humanus capitis) that live on the scalp and can be spread by close contact with other people.

Causes, incidence, and risk factors:

There are three common types of lice: head lice, body lice, and pubic lice. Head lice infect the scalp hair and are easiest to see at the nape of the neck and over the ears. Small eggs (nits) can be seen on the hair shafts. They appear much like flakes of dandruff, but are stuck firmly to the hair shaft instead of flaking off of the scalp. Head lice do not cause a serious medical problem and do not spread other diseases (as body lice do), but they are spread very easily. Risk factors include close, overcrowded living conditions, and poor hygiene. Lice spread readily among school children.

It is important to note that having lice is not an indicator of poor hygiene or low socioeconomic status.

Update Date: 02/09/00
Updated by: J. Gordon Lambert, MD, Associate Medical Director, Utah Health Informatics and adam.com editorial