Head lice, a common parasitic infestation known medically as pediculosis capitis, often causes immediate concern about how to remove the tiny insects and their eggs. Head lice are wingless insects that live exclusively on the human scalp, feeding on small amounts of blood. The adult female louse lays eggs, called nits, which are firmly cemented to the hair shaft close to the scalp, typically in warm areas like the nape of the neck and behind the ears. The most effective approach for achieving a lice-free head involves using specialized tools and proven treatment methods.
The Limitations of Manual Removal
Pulling lice and nits out with the fingers is a highly ineffective method for clearing an infestation. Adult lice are small and fast-moving, making them difficult to spot and nearly impossible to reliably catch with the fingers alone. They spend their entire life cycle on the host, and their quick movements allow them to evade capture easily.
The primary reason this method fails is the remarkable strength of the nit’s attachment to the hair shaft. Female lice secrete a specialized, cement-like glue that fixes the egg firmly in place. This adhesive is so strong that it resists ordinary washing and cannot simply be plucked off without often breaking the hair. Nits require a physical tool designed to slide them off the hair rather than merely a tugging motion.
The Mechanics of Effective Combing
The most reliable physical method for removing both live lice and nits involves a technique called wet combing. This process requires a specialized fine-toothed metal nit comb, which has teeth spaced narrowly enough to trap the tiny insects and eggs. Preparation involves generously applying hair conditioner or a specific lice oil to the hair. This helps to untangle the hair and temporarily slow the movement of the lice, allowing the comb to glide more easily and dislodge the firmly attached nits.
The technique requires dividing the hair into small, manageable sections, often four quadrants, which are then worked through systematically. The fine-toothed comb must be placed flat against the scalp and drawn firmly down the entire length of the hair, from root to tip. After each stroke, the comb should be checked for lice or nits and wiped clean on a paper towel or rinsed in hot water. Wet combing is a time-consuming process that must be repeated every three to four days for at least two weeks to ensure any newly hatched nymphs are removed before they can mature and lay new eggs.
Chemical Treatments and Environmental Cleaning
In addition to meticulous combing, chemical or non-chemical topical treatments are often used to kill the live lice. These treatments, known as pediculicides, are available as over-the-counter or prescription shampoos and lotions. Treatments are applied to dry hair and must be left on for the recommended duration before rinsing. Some treatments are strongly ovicidal, meaning they kill the eggs, while others only kill the crawling lice.
For treatments that are not fully ovicidal, a second application is usually recommended seven to nine days after the first treatment to kill any newly hatched nymphs. Environmental cleaning efforts are generally minimal because head lice do not survive for long once separated from the human host. However, it is prudent to machine wash and dry clothing, bedding, and towels used by the infested person in the two days prior to treatment using hot water and a high heat drying cycle. Items that cannot be laundered, such as certain hair accessories, can be sealed in a plastic bag for two weeks to ensure any remaining lice or nits are killed.