Head lice are a common concern, particularly among school-aged children. Applying mayonnaise to the hair has gained attention as a home remedy. This article examines claims about mayonnaise treating lice eggs, known as nits, and provides evidence-based information on effective management strategies.
Understanding the Mayonnaise Method
The theory behind using mayonnaise for head lice is suffocation. Proponents suggest its thick, oily consistency can coat and block the breathing pores, called spiracles, of live adult lice, leading to their demise. Application typically involves saturating hair and scalp with mayonnaise, covering the head with a shower cap, and leaving it on for several hours or overnight. Mayonnaise is sometimes considered due to being an inexpensive and readily available household item.
Why Mayonnaise is Ineffective for Nits
Despite its theoretical suffocating effect on adult lice, mayonnaise is generally ineffective against nits. Nits are encased in a hard, protective shell that mayonnaise cannot penetrate or dissolve. They are firmly glued to the hair shaft with a strong, water-insoluble adhesive, making them resistant to removal by simply washing out the mayonnaise. Nits do not breathe like adult lice, rendering suffocation attempts futile. Even if mayonnaise incapacitated some live adult lice, unaffected nits would hatch within days, leading to a renewed infestation cycle.
Effective Lice Treatments
Scientifically proven treatments for killing live lice include over-the-counter (OTC) and prescription options. OTC products often contain active ingredients like pyrethrins (natural insecticides from chrysanthemums) or permethrin (a synthetic pyrethroid), found in brands such as Nix or Rid. Both disrupt the lice’s nervous system, causing paralysis and death. Following package directions precisely is important, including a second application 7 to 10 days later to address newly hatched lice.
For cases where OTC treatments are not effective, prescription medications are available. These include malathion lotion (Ovide), which affects the lice’s nervous system, and benzyl alcohol lotion (Ulesfia), which suffocates lice. Spinosad topical suspension (Natroba) kills both live lice and unhatched eggs, often eliminating the need for retreatment. Ivermectin lotion (Sklice) causes paralysis in lice; while it does not kill eggs, it prevents newly hatched nymphs from surviving.
Manual Nit Removal
Even with chemical treatments, manually removing nits is an important step for managing head lice. This process involves dampening the hair and applying conditioner to help detangle it and make combing easier. Using a fine-toothed lice comb is important for this task. Hair should be divided into small sections, and the comb systematically drawn from the scalp to the end of the hair.
After each stroke, the comb must be wiped clean on a paper towel or tissue to remove any lice or nits. This thorough combing should be repeated every two to three days for at least two weeks to ensure all newly hatched lice are caught before they can mature and lay more eggs. Combs and brushes used during the process should be cleaned by soaking them in hot water (at least 130°F or 54°C) for 5-10 minutes or in rubbing alcohol.