What are lice?
Lice are tiny brown and grey parasites that cause itching and scratching, especially on areas of the body that are covered with hair (typically the scalp, neck, and behind the ears). These insects do not transmit any disease but are annoying. Lice infestation spreads easily - especially by children - through close personal contact and by sharing personal belongings. The head louse, Pediculus humanus capitus, though very small (2 mm to 4 mm long), can be seen by the human eye. Lice live among human hairs, draw blood from the skin and lay eggs (nits) on hair shafts, close to the skin surface, where the temperature is perfect for incubation. They have tiny claws on their legs that are adapted for feeding and clinging to hair or clothing.
There are different types of lice:
- Head lice: These lice grow on the scalp. They are easiest to see at the nape of the neck and over the ears. Small eggs (nits), produced by lice, attach to the hair shafts. The eggs hatch in about 1 week, resulting in more lice.
- Body lice: These lice burrow into the skin and are difficult to find on the body. They can usually be detected in the seams of the underwear. Body lice are often spread by contact with infected clothing or bedding.
- Pubic lice: Commonly called crabs, these lice occur on the skin and hair of the pubic areas and on eyelashes. Sexual contact or contact with infected clothing, bedding or even toilet seats can spread pubic lice.
What are the signs and symptoms?
Intense itching is the first symptom of lice infestation. Lice are found on the scalp, body, clothing and pubic or other body hair. They can be up to 1/8 inch (3 millimetres) in size.
What is the cause?
One can get lice by coming in contact with either live lice or their eggs. The eggs hatch within 1 to 2 weeks after they are laid, and newly hatched lice bite within 24 hours of hatching. However, itching doesn't always start right away. It depends on how sensitive a particular person's skin is to the lice bites.
They spread by:
- head or body-to-body contact. This may occur as children or family members play or interact closely together.
- Storing clothing such as coats, hooded sweatshirts, scarves next to each other in cupboards or on side-by-side hooks at school, or storing personal items such as pillows, blankets, combs, brushes and stuffed toys in close proximity at home.
- Sharing items such as clothing, headphones, brushes, combs, hair decorations, towels, blankets, pillows and stuffed toys.
- Lying on a bed, or even using a toilet seat recently occupied by someone infected with lice. All three forms of lice can be spread by sexual contact.
How are lice treated?
If a non-prescribed lotion or shampoo doesn't kill the lice, the doctor can prescribe a stronger prescription shampoo containing the medication lindane. This is not recommend for preschool children or for pregnant women. Medicated shampoos, creams, and lotions can end a lice infestation right away, but it may take about 5 days for the itching to stop.
The treatment for lice involves self-care steps which can be taken at home to make sure all the nits are removed and that all clothing, bedding, personal items and furniture are decontaminated. In most cases killing lice on the body is not difficult. It is important to get rid of all the nits and avoiding contact with other lice in the home or school environment.
Washing clothing and bed linens in very hot water or putting them in airtight bags for 10 days can help kill the lice and their eggs. Hair-care items, like combs and brushes, can either be soaked in hot water or medicated shampoo or thrown away. Because lice infestations are easily passed from person to person in the same house, members of the family may need treatment for lice infestation to prevent lice from coming back.
For head lice specifically:
After shampoo treatment, rinse hair with vinegar. Grasp a lock of hair with a cloth saturated with vinegar and strip the lock downward to remove nits. Repeat until all the hair is treated in this way. Then towel-dry the hair. This method is usually more effective than using tweezers or a fine-toothed comb to remove any remaining nits. Keep children, infected with lice, at home until the first round of treatment is completed. Soak combs and brushes in very hot, soapy water for a minimum of 5 minutes.
What is the prevention?
Lice are highly contagious. Although they don't fly in the air or walk on the ground, they can pass from one person to another through clothing, bed linen, combs, brushes, and hats. It is difficult to prevent the spread of head lice as it spreads very easily but the following can be done:
- Avoid physical contact with people who have lice.
- Do not share combs, brushes, hats, scarves, ribbons, or other personal items.
- Examine and treat members of the household who have had close contact with a person infected with lice.
- Keep the child home from school or day care until the morning after treatment for lice.
- Avoid garments and bedding that may be contaminated.