Head lice infestations are common, especially among school-aged children. These tiny, contagious parasites feed on human blood and cause discomfort, leading many to seek treatment. Among the various options, the home remedy of using mayonnaise to eliminate lice is a popular belief.
The Claim and Its Basis
Mayonnaise as a head lice treatment is a long-standing home remedy, based on the idea that its thick, oily consistency can smother the parasites. Proponents suggest mayonnaise coats lice, blocking their breathing pores (spiracles) and suffocating them. Application involves saturating hair and scalp with mayonnaise, covering with a shower cap, and leaving it on for several hours, often overnight. This is seen as a natural, chemical-free alternative to commercial treatments.
Why Mayo Fails
Despite widespread belief, mayonnaise is not an effective head lice treatment. Lice can close their spiracles (breathing holes) for extended periods, surviving without oxygen for many hours. This allows them to endure submersion in substances like mayonnaise, preventing suffocation. Even if some live lice are temporarily stunned or slowed by the thick coating, they are unlikely to be reliably killed.
A significant limitation is mayonnaise’s inability to impact lice eggs, known as nits. Nits are firmly attached to the hair shaft and protected by a hard outer shell that mayonnaise cannot penetrate. Even if adult lice are affected, nits remain viable and hatch within seven to ten days, leading to renewed infestation. Relying on mayonnaise can delay proper treatment, prolonging the problem.
Proven Lice Treatments
Effective head lice treatment involves medicated products and manual removal. Over-the-counter (OTC) options are often the first defense, containing insecticides like permethrin (e.g., Nix) or pyrethrins with piperonyl butoxide (e.g., Rid). Permethrin affects the lice’s nervous system and is approved for individuals as young as two months. Pyrethrins are suitable for those aged two years and older. These treatments often require a second application seven to ten days after the first to kill newly hatched lice.
When OTC treatments are not effective, or for more severe infestations, prescription medications are available. These include topical lotions like Ivermectin (Sklice), Malathion (Ovide), Spinosad (Natroba), and Benzyl alcohol (Ulesfia). Ivermectin lotion can kill most lice with a single application and often does not require nit combing. Spinosad kills both live lice and nits, often eliminating the need for retreatment or nit combing. Malathion paralyzes and kills lice and some eggs, while benzyl alcohol suffocates live lice, though it does not kill eggs, necessitating a second treatment.
Manual removal through wet-combing is a key component of any successful lice management strategy, regardless of medicated product use. This method involves wetting the hair, applying conditioner to detangle and stun lice, then systematically combing through small sections with a fine-toothed nit comb from roots to tips. The comb should be wiped on a paper towel after each stroke to remove lice or nits. The process should be repeated every few days for at least two to three weeks until no lice or nits are found. This physical removal helps ensure all stages of the lice life cycle are addressed.
Environmental cleaning is also part of managing an infestation, though it is less extensive than often assumed. Head lice cannot survive for long periods (24 to 48 hours) off a human host, and nits require body heat to hatch. Therefore, focus cleaning on items in direct contact with the infested individual’s head in the 48 hours prior to treatment. This involves washing bedding, clothing, and towels in hot water (at least 130°F) and drying them on high heat. Non-washable items, such as stuffed animals or headphones, can be sealed in a plastic bag for two weeks or placed in a dryer on high heat for at least 30 minutes; vacuuming carpets, rugs, and upholstered furniture is also helpful to remove any stray lice.