What are lice?
It’s the call from the school nurse that no parent likes to hear: “Your child has head lice.” It is estimated that 6 to 12 million children under the age of 11 become infested with head lice every year. Though head lice are not exclusively a childhood ailment, the majority of people affected by head lice are young.
The head louse, scientific term Pediculus humanus capitis, is a parasite that feeds on human blood. Learning what head lice look like and how to detect them can help control an infestation before it spreads through the entire household.
Three forms of lice
Three forms of head lice exist: nits, nymphs, and mature adults. Nits are lice eggs that attach to the hair shaft and usually hatch within a week. The microscopic eggs are easy to mistake for dandruff or residue from hair styling products.
Once the eggs hatch, lice are known as nymphs, an immature form of the parasite that is grayish tan in color. After nine to 12 days the nymphs mature into adults, the average size of which is roughly 2–3 millimeters, or about the size of a sesame seed.
Where do head lice live?
Head lice feed on blood and therefore stay close to the scalp where there is an abundant supply of food. After the nits hatch, they move from the hair shafts to your scalp to find sustenance.
You’ll find nymph and adult lice most commonly on the scalp around the back of your neck and ears. They might also live in your eyebrows or on your eyelashes. When fed, head lice can live for up to a month, but they will die within a day or two if they are not able to feed on blood.
Head lice are insects, but they can’t fly. Instead, they crawl around in your hair and on your scalp to get nourishment. Lice are spread through close personal contact. The parasites crawl onto your clothing, hairbrushes, hats, towels, and any other personal belongings.
If a friend or family member shares your comb or scarf, the head lice can crawl onto the new host and lay eggs, spreading the infestation. Female head lice can lay several eggs each day. Household pets and other animals do not spread head lice to humans.
Detecting head lice: Symptoms
Some people experience the uncomfortable symptoms of head lice before noticing them in the hair, while others are asymptomatic. Head lice bite you in order to feed off your blood. The parasites’ saliva is irritating to many people, causing itching of the scalp. You might develop sores or red, raised bumps on your scalp from scratching your head without realizing why you are itchy at first.
Other symptoms that alert you to a case of head lice include a ticklish feeling on your head, especially at night. The head louse is a nocturnal creature and is more active in the dark than during the light of day.
Detecting head lice: Visual inspection
A visual inspection of your hair and scalp is usually effective in detecting head lice, though the creatures are so small that they can be difficult to spot with the naked eye.
Parting your hair in small sections and literally going through each section with a fine-tooth comb is a painstaking but necessary step to find and remove head lice. A bright light and a magnifying glass are useful tools to aid in the detection and diagnostic process.
Head lice are treated through manual removal with a comb as well as special shampoos containing chemicals that kill lice. Even if just one nit or adult louse is found, treatment is advised to reduce the threat of a full infestation.
Clothing, bedding, and towels must all be washed in hot water to control the infestation. Vacuuming carpets and furniture upholstery is another component of the treatment process for head lice.
Outlook and prevention
The good news is while a head lice infestation can be annoying and possibly uncomfortable, this common condition is treatable. Complications are rare and generally limited to skin infections caused by scratching.
Prevent head lice by instituting a “no sharing” rule for personal belongings such as combs, hairbrushes, towels, hats, and bedding.