How and with what can lice be poisoned? - briefly
Effective lice control uses topical neurotoxic agents such as permethrin, pyrethrins, malathion, ivermectin, or spinosad, and suffocating compounds like dimethicone silicone oil. Applied according to label instructions, they eliminate infestations within one to two weeks.
How and with what can lice be poisoned? - in detail
Lice eradication relies on toxic agents that disrupt the insects’ nervous system, respiratory function, or structural integrity. The most effective chemical classes include:
- Pyrethroids (permethrin, pyrethrin): bind to voltage‑gated sodium channels, causing paralysis and death. Formulated as shampoos, lotions, or sprays; resistance is common in many populations.
- Neonicotinoids (imidacloprid, acetamiprid): act on nicotinic acetylcholine receptors, leading to uncontrolled nerve firing. Available in topical solutions and foam applications.
- Organophosphates (malathion): inhibit acetylcholinesterase, resulting in accumulation of acetylcholine and fatal overstimulation. Provided as liquid rinse; requires careful dosing to avoid skin irritation.
- Oxadiazines (spinosad): interfere with neuronal signaling, causing rapid knock‑down. Used in spray formulations for head lice and body lice.
- Insect growth regulators (hydroprene, methoprene): mimic juvenile hormone, preventing molting and reproduction. Applied as shampoos; effectiveness depends on sustained exposure.
Non‑chemical options that act as poisons include:
- Silicone‑based lotions (dimethicone): coat the exoskeleton, suffocating the organism by blocking spiracles. Applied to hair and left for several hours before removal.
- Essential oil preparations (tea tree oil, eucalyptus oil, neem oil): contain terpenes and azadirachtin that impair respiratory function and disrupt cuticle integrity. Typically mixed with carrier oils and applied as a rinse.
- Heat treatment: exposure to temperatures above 50 °C for a minimum of 30 minutes denatures proteins and kills lice. Implemented with specialized steam devices or hot air dryers.
Application protocols must ensure contact with all life stages—eggs, nymphs, and adults. Recommended steps:
- Wet hair thoroughly, apply the chosen product according to label instructions, ensuring complete coverage from scalp to tips.
- Maintain the prescribed exposure time; for liquid formulations, this often ranges from 10 to 30 minutes.
- Rinse with lukewarm water; for silicone or oil‑based treatments, comb the hair with a fine‑toothed nit comb to remove dead insects and residual material.
- Repeat treatment after 7–10 days to target newly hatched nymphs that survived the initial exposure.
- Launder bedding, clothing, and personal items at ≥60 °C or seal them in plastic bags for two weeks to prevent re‑infestation.
Safety considerations include avoiding products containing neurotoxic agents on infants under two months, pregnant women, or individuals with known skin sensitivities. When using essential oils, limit concentration to ≤1 % to reduce irritation risk. Proper ventilation and protective gloves are advisable when handling organophosphates or pyrethroids.