Head lice are a common problem, especially for children, often causing frustration due to recurrent infestations. These tiny, sesame-seed-sized insects feed on human blood from the scalp. While not dangerous or disease-spreading, their persistent presence can be upsetting. This article explores the reasons why infestations return and offers effective strategies to address them.
How Lice Are Transmitted
Head lice primarily spread through direct head-to-head contact, common among children during activities like playing, sports, or sleepovers. Lice are wingless parasites that crawl, unable to jump or fly, moving from one person’s hair to another.
Less commonly, lice can spread via shared personal items such as combs, brushes, hats, scarves, or headphones that have contacted an infested person. Pets do not carry human lice, so household animals are not a source of infestation.
Why Infestations Return
Recurring head lice infestations often stem from several factors. Incomplete treatment is a common reason, where not all live lice or their eggs, known as nits, are eliminated during the initial treatment. Nits are tiny and firmly glued to hair shafts, making them difficult to spot and remove entirely; any missed viable eggs can hatch, restarting the life cycle.
Misdiagnosis also contributes to recurrence, as nits might be confused with dandruff or other debris, leading to ineffective treatments. Additionally, some head lice populations have developed resistance to certain over-the-counter pediculicides like permethrin and pyrethrins. This resistance means treatments that once worked may no longer fully kill all lice, allowing some to survive and reproduce.
Immediate re-exposure is another significant cause. A child can quickly become re-infested if they come into contact with an untreated family member, close friend, or classmate who still carries lice. This emphasizes the need to check and treat all close contacts to prevent re-infestation within a household or social group.
Ensuring Effective Treatment
Effective treatment of an active lice infestation is important to prevent recurrence from incomplete removal. Over-the-counter options like permethrin and pyrethrins typically kill live lice but may not be fully effective against all nits. Prescription options, such as malathion, spinosad, or ivermectin lotion, may be considered for resistant cases or if initial treatments are unsuccessful.
Following product instructions precisely is important for treatment success, including recommended application times and the timing of follow-up treatments, usually 7 to 9 days later. Thorough nit combing with a fine-toothed lice comb is also a complementary and effective step. This process involves systematically combing through wet hair, from scalp to tip, to physically remove nits and any remaining lice.
While treating the infested individual is the primary focus, some environmental measures can be taken. These are generally less critical than treating the head. Washing bedding and clothing in hot water and vacuuming can help, but lice typically do not survive long off a human host. Sealing non-washable items in plastic bags for about two weeks can also address any lingering lice.
Preventing Re-infestation
After successful treatment, proactive strategies help prevent a child from catching lice again. Regular head checks are useful, especially for children in school or daycare settings. Parents can perform weekly checks, focusing on areas behind the ears and at the nape of the neck, where lice and nits are often found.
Educating children about avoiding head-to-head contact during play and not sharing personal items like hats, combs, or hair accessories can reduce transmission risk. Communicating with schools or daycare providers is also beneficial; informing them about infestations can facilitate broader checks and help prevent outbreaks within the community.
It is important to check all household members if lice are found on one person. Asymptomatic carriers, individuals with lice but no symptoms, can inadvertently lead to re-infestation if not identified and treated concurrently. Keeping long hair tied up or braided can also reduce the likelihood of head-to-head contact and subsequent transmission.