“Super lice” are head lice that have developed genetic resistance to the active ingredients in some traditional over-the-counter (OTC) lice treatments. They are a variant of common head lice, distinguished by their evolved resistance rather than appearance or behavior. Super lice look and act exactly like regular head lice, maintaining the same size, color, and life cycle.
Understanding Resistance
Super lice are head lice that have genetically mutated, making them resistant to common over-the-counter pediculicides, especially those containing pyrethrins and permethrin. These insecticides are synthetic versions of natural compounds, like those found in chrysanthemum flowers, and work by targeting the lice’s nervous system. Widespread and sometimes improper use of these treatments has led to natural selection, favoring lice with genetic mutations that allow them to survive exposure. Studies have shown high levels of these gene mutations in lice populations across various regions, indicating a significant reduction in the effectiveness of permethrin and pyrethrin-based products. This resistance means traditional treatments may fail to eliminate an infestation.
Identifying an Infestation
Identifying a super lice infestation involves looking for the same signs as a regular head lice infestation. The most common symptom is intense scalp itching, which is often due to an allergic reaction to bites. Other indicators include a tickling sensation, red bumps or sores from scratching, and difficulty sleeping as lice are more active at night.
To confirm an infestation, look for live lice, which are tiny, tan to grayish insects about the size of a sesame seed, found crawling on the scalp and hair. Lice eggs, called nits, are also a key sign. They appear as tiny, oval-shaped specks, often white, yellowish, or brown, firmly attached to hair shafts close to the scalp. Unlike dandruff, nits are difficult to remove and do not flake off easily. A fine-toothed comb, preferably a metal nit comb, used on wet hair can help detect both live lice and nits, especially behind the ears and at the nape of the neck.
Effective Treatment Strategies
Effective strategies for super lice often involve different approaches due to their resistance to traditional over-the-counter chemical treatments. Prescription medications are frequently recommended for resistant infestations. These include topical solutions like spinosad, which causes paralysis and death in lice, and malathion lotion, which affects their nervous system. Ivermectin, available as a topical lotion or oral tablet, is also highly effective.
Non-pesticide treatments offer effective alternatives. Dimethicone, a silicone-based product, works by physically coating and suffocating lice and nits. Manual wet-combing with a fine-toothed nit comb is another viable method, especially when combined with a conditioner to slow down the lice. This method requires persistence and should be repeated every few days for at least two weeks to ensure all newly hatched lice are removed before they can lay eggs.
Preventing Spread and Reinfestation
Preventing the spread and reinfestation of super lice focuses on avoiding direct head-to-head contact, the most common transmission method. Encourage children to avoid activities where heads might touch, like during play or sleepovers. Avoid sharing personal items that contact hair, such as hats, scarves, combs, brushes, and headphones.
Cleaning certain household items offers additional protection. Wash bedding, clothing, and hats worn by an infested individual in hot water (at least 130°F) and dry them on a high heat setting. Items that cannot be washed can be sealed in a plastic bag for two weeks, as lice cannot survive long off a human host. Regular scalp checks, especially in children and close contacts, using a fine-toothed comb, can help detect new infestations early.