Head lice are small parasitic insects that live on the human scalp. When faced with an infestation, a common concern is whether it is safe to sleep in your own bed. The answer is generally yes, though taking specific cleaning and treatment steps is important. Understanding their biology and managing your environment can help alleviate concerns and prevent re-infestation. The risk of contracting lice from bedding or other surfaces is low, but taking action remains a necessary part of managing an infestation.
Lice Survival Outside the Scalp
Head lice require human blood to survive. An adult louse lives up to 30 days on a person’s head, but they will die within one to two days if they fall off the scalp and cannot feed. Without regular blood meals, lice quickly become dehydrated. This short survival time off a host reduces the risk of transmission from environmental surfaces.
Lice move by crawling and cannot jump or fly. Their legs are adapted to grasp human hair shafts, making it difficult for them to move on smooth surfaces or objects. Therefore, transmission occurs through direct head-to-head contact. While adult lice can fall onto objects like bedding, their inability to jump and short survival time outside the scalp make it uncommon for them to transfer back to a new host from these surfaces.
Lice eggs, known as nits, are firmly glued to hair shafts close to the scalp. They need the warmth and humidity of the scalp to hatch. If nits become dislodged from the hair, they are unlikely to hatch because they require the temperature conditions of the scalp. Nits can survive up to 10 days off the scalp, but they die within a week if not kept at the optimal temperature. This biological necessity further minimizes the risk of re-infestation from eggs found on inanimate objects.
Cleaning Your Environment After Lice
Cleaning your environment, especially your bed and bedding, is an important step after a head lice infestation. Machine wash and dry clothing, bed linens, and items that contacted the infested person’s head within 48 hours before treatment. Use hot water (at least 130°F or 54°C) for washing, then dry items on a high heat cycle for at least 20 minutes to kill lice and nits.
For items that cannot be machine washed, such as stuffed animals or pillows, they can be dry-cleaned or sealed in a plastic bag for at least two weeks. This period ensures that any lice present will die from lack of a blood meal and any nits will hatch and subsequently die without a host. Vacuuming mattresses, upholstered furniture, and carpets is recommended to remove any lice or nits that may have fallen off. Lice do not burrow into mattresses, so they would be on the surface, making vacuuming or using a sticky lint roller effective.
Combs, brushes, and hair accessories used by an infested person should also be cleaned. These items can be cleaned by soaking them in hot water (at least 130°F or 54°C) for 5 to 15 minutes. Alternatively, they can be placed in a sealed plastic bag for two weeks or put in a dishwasher on a sanitize cycle.
Preventing Re-infestation
Preventing re-infestation involves treating the infested individual and checking close contacts. Treating the person with head lice is the most important step, as environmental cleaning alone is insufficient to stop the cycle. Use an FDA-approved lice treatment and follow the instructions for application and re-treatment if necessary.
It is important to check all household members for lice, as infestations often spread within families due to close contact. Regular head checks, especially during outbreaks, can help identify new infestations early. Avoiding head-to-head contact during play and other activities is a preventive measure.
Discouraging the sharing of personal items that touch the head can also help prevent spread. This includes hats, scarves, hair accessories, combs, brushes, and towels. While less common, lice can transfer through these items if they have been recently used by an infested person. Understanding these transmission routes complements treatment efforts and helps prevent lice from returning.