Understanding and Managing Head Lice: A Comprehensive Guide
Dealing with head lice can be a challenging and frustrating experience. Despite the availability of various treatments like special combs and shampoos from pharmacies, completely eliminating these tiny pests often requires more than just standard products. A thorough understanding of how head lice live, spread, and survive is crucial to eradicating them for good.
What Are Head Lice?
According to the U.S. Centers for Disease Control and Prevention (CDC), head lice are tiny insects about the size of a sesame seed. These parasites feed on human blood from the scalp, and when they bite, they release saliva that can cause an allergic reaction, leading to an itchy sensation. Head lice have a lifespan of approximately 30 days, during which female lice can lay up to eight eggs, known as nits, each day. Unlike body lice, head lice do not jump or fly; they move by crawling. While they do not transmit diseases, head lice infestations can be a significant nuisance.
How Do Head Lice Spread?
Head lice primarily spread through direct contact, crawling from one person’s head to another’s. They can also be transmitted through shared items such as scarves, combs, towels, hair ties, pillows, sheets, and coats—anything that comes into contact with an infested person’s hair. Even if lice fall off the head, they can survive on surfaces for up to 48 hours without feeding. As soon as a potential host is nearby, the lice will move toward them to feed, according to Rosario Melero, a medical parasitology expert at the Fundación iO in Madrid, Spain.
Can Lice Survive in Water?
Yes, lice can survive for several hours in water, meaning they can potentially be contracted in swimming pools. Their bodies are adapted to float, and they can cling to hair more easily when it is wet, Melero explains.
Who Is Most at Risk of Getting Lice?
Children are particularly vulnerable to head lice infestations. This is partly because they do not undergo the hormonal changes that occur in adults, which lice tend to avoid. Additionally, children have thinner skin, making it easier for lice to bite. The close physical contact that children often have with one another, such as at school or during play, also facilitates the spread of lice.
Girls, who often have longer hair than boys, are more likely to get lice, as it is easier for the insects to move from one strand of hair to another. Similarly, within families, mothers are more likely to contract lice from their children, particularly if they have long hair and are involved in delousing their kids. However, anyone with long hair who assists a child with lice can be at risk.
Does Frequent Hair Washing Help Prevent Lice?
No, washing your hair more regularly does not prevent lice. In fact, Melero points out that clean hair may actually make it easier for lice to reach the scalp.
Why Are Lice So Difficult to Get Rid Of?
One of the main challenges in getting rid of lice is detecting them and their eggs, or nits, in the first place. Often, people may not realize they have lice because they cannot see them, especially if there is only one louse on the scalp or if the hair is dark. Nits are so small that they can easily be mistaken for dandruff, especially when they are laid behind the ears, according to dermatologist Yael Adler.
Melero suggests that a stronger emphasis on lice prevention, similar to mosquito and malaria prevention, would be beneficial. There are repellents available that can be applied to the scalp to prevent lice from biting or laying eggs. Additionally, using a fine-toothed comb several days after lice are first detected can help eliminate any remaining eggs.
What Can You Do If You Have Lice?
The most common treatment for lice is the use of insecticidal shampoos. These shampoos must be applied multiple times to ensure that all live lice are killed. However, they are often less effective against nits. To combat this, silicone oil can be applied to the hair and scalp. After soaking for ten minutes, the lice should be dead and can be removed with a nit comb. This process should be repeated after eight days to ensure any remaining nits are also eliminated. It is also advisable for the entire family to undergo treatment to prevent re-infestation.
Clothing and items that have come into contact with lice should be washed at 60 degrees Celsius (140 degrees Fahrenheit). Items that cannot be washed at high temperatures can be placed in a freezer for several hours or sealed in a bag for a few days to kill any lice or nits. Always consult your family doctor or general practitioner for further advice and treatment options.