What happens if you treat lice with dichlorvos? - briefly
Dichlorvos rapidly eliminates head‑lice infestations, typically killing the insects within a few hours; however, it is a potent organophosphate that can cause respiratory irritation, seizures, and other serious neurotoxic effects in humans, leading many health agencies to ban its use for pediculicide treatment.
What happens if you treat lice with dichlorvos? - in detail
Dichlorvos, an organophosphate compound, inhibits acetylcholinesterase, causing accumulation of acetylcholine at synaptic junctions. In lice, this biochemical disruption leads to uncontrolled nerve firing, muscle contraction, paralysis, and death within minutes of exposure.
Efficacy observations include:
- Rapid immobilization of adult and nymph stages.
- Mortality rates exceeding 90 % when applied at label‑recommended concentrations.
- Residual activity diminishing within 24–48 hours due to volatilization and degradation.
Safety profile presents significant concerns:
- High acute toxicity to mammals; dermal absorption can produce cholinergic symptoms such as sweating, nausea, bradycardia, and respiratory distress.
- Children and pregnant individuals exhibit heightened vulnerability.
- Inhalation of vapors may trigger neurological effects even at low environmental concentrations.
Regulatory agencies in many jurisdictions have restricted or prohibited use for pediculosis treatment. The United States Environmental Protection Agency classifies dichlorvos as a restricted-use pesticide for lice, while the European Union has withdrawn marketing authorizations for household applications.
Practical considerations for application:
- Formulations typically supplied as liquid concentrates requiring dilution to 0.1–0.2 % w/v.
- Direct scalp spray or shampoo infusion ensures contact with hair shafts where lice reside.
- Protective equipment (gloves, masks) mandatory for applicators to mitigate exposure.
- Repeated treatments generally unnecessary; a single application achieves complete eradication if correctly executed.
- Development of resistance documented in some populations, reducing long‑term reliability.
Alternative pediculicides, such as dimethicone‑based lotions or ivermectin oral therapy, offer comparable efficacy with markedly lower toxicity. Selection of treatment should weigh rapid knock‑down capability against potential health hazards and legal restrictions. «Studies demonstrate that dichlorvos achieves swift lice mortality but poses unacceptable risk to human users, leading to its phase‑out in favor of safer agents.»