Lice are small, parasitic insects that can live on the scalp. They feed on human blood, but they don’t spread diseases. They can only survive for 24 hours without a host. Anyone can get head lice, but they’re more common among children.
Lice can’t fly or jump, but they can crawl. They can spread from person to person through direct contact or by sharing personal items. For example, sharing towels, hairbrushes, and hats can spread lice. But how does swimming affect lice?
Does chlorinated water kill lice?
Research shows that lice can survive pool water treated with chlorine. One study that involved submerging lice in chlorinated water for 20 minutes found that although lice were temporarily immobilized, they fully recovered less than a minute after being taken out of the water.
Chlorine can’t kill head lice. The Centers for Disease Control and Prevention (CDC) also report that swimming in a chlorinated pool won’t kill lice. Not only are lice able to survive pool water, but they also firmly grip human hair when a person goes under water.
Risks of using chlorine on the head
Don’t use a more powerful chlorine solution on your head or your child’s head to kill lice. A higher concentration of chlorine won’t kill the insects and could lead to serious side effects including:
- burns and blisters on the skin
- eye damage or blindness
- nausea and vomiting
- tightness in the chest
- breathing problems
- pain and redness
- burning feeling in the nose and throat
Can lice spread from person to person in a pool?
Head lice don’t spread from person to person in a pool. In one study, four individuals with head lice swam in a pool with others who did not have head lice. The lice survived as expected, but they did not spread to those who were not already infected. Since lice hold on to the hair tightly and don’t move into the water, it’s unlikely they can spread to another person.
However, as the CDC notes, sharing personal items associated with swimming can spread lice. This includes towels used to dry hair, hats used for sun protection, combs or brushes, and other items that come in contact with the head.
Treatment for lice
You have many treatment options for head lice. Treatment usually involves applying creams, lotions, or liquids to the scalp.
Over-the-counter medications for lice include:
- permethrin lotion
Prescription medications for head lice include:
- benzyl alcohol lotion
- ivermectin lotion
- malathion lotion
- spinosad topical suspension
- lindane shampoo
Supplementary treatment includes:
- using a nit comb to remove lice
- using an electric comb to kill lice
- washing all the clothing and personal items that belong to the person who has lice
- sealing items that can’t be washed in plastic bags for two weeks
You want to avoid the following home remedies because they aren’t proven to work and may be dangerous. Don’t use:
- olive oil
- petroleum jelly
Does chlorine interfere with lice treatment?
Although chlorine can’t kill head lice, it can interfere with some lice treatments. It’s important to avoid swimming in a pool or washing your hair 24 to 48 hours after applying some lice treatments to the scalp. For example, Nix treatment may not work as well if it’s exposed to chlorine in a pool. Check the instructions for the medication you’re using and talk to your doctor about any questions.
In general, it’s best to avoid washing your hair in any liquid for one to two days while using lice treatments. Washing can influence the effectiveness of the treatments.
Chlorine can’t kill head lice, so swimming in a chlorinated pool won’t get rid of them. Also, swimming is unlikely to spread lice to another person in the pool.
Ask your doctor about lice treatments and avoid home remedies that aren’t proven to work. Prevention of head lice is possible. Remind your kids to avoid close contact with those who are infected and not to share personal items such as hairbrushes or hats.