Copyright © Nucleus Medical Media, Inc.
Definition
Head lice are tiny, barely visible insect-like animals (“arthropods”) that may live on the head and cause itching. ("Lice" is plural; the singular is "louse.") Head lice may also live in the eyebrows, eyelashes, and beard. However, sometimes infestations in these areas are from a related species called pubic lice.
Causes
Head lice spread by personal contact and by sharing combs, brushes, hats, and other personal items.
Risk Factors
A risk factor is something that increases your chance of getting a disease or condition. Risk factors include:
- Age: childhood
- Sharing combs, brushes, hats, and other personal items
- Personal contact with people who may have lice
Symptoms
Symptoms include:
- Extreme itchiness
- Skin breaks and possible infection (caused by scratching)
- Swollen lymph nodes
- Bacterial infection (if scratching causes open areas on the scalp)
- Some persons with head lice do not have symptoms.
Diagnosis
The doctor will ask about your symptoms and medical history. A physical exam will be done. The doctor will examine your head and scalp for lice and lice eggs (called "nits").
Do not self-diagnose and self-treat head lice. Some treatments can cause irritation and should only be used by people who have the in