How long should dichlorvos be left on the head to treat lice? - briefly
Apply the dichlorvos preparation for about ten minutes, then rinse thoroughly. Extending the exposure beyond this period offers no additional benefit and may increase irritation risk.
How long should dichlorvos be left on the head to treat lice? - in detail
Dichlorvos (commonly known by the trade name DDVP) is a fast‑acting organophosphate used in some lice‑removal products. The label and clinical guidelines specify a contact period of 10 minutes before the solution is rinsed off. This interval allows sufficient absorption by the lice to interrupt their nervous system, leading to rapid paralysis and death.
Key points for safe and effective use:
- Application: Apply the liquid evenly to dry hair, ensuring the scalp and all hair shafts are saturated. Use a fine‑toothed comb to spread the product if instructed.
- Timing: Maintain the solution on the scalp for exactly ten minutes. Do not exceed this duration, as prolonged exposure increases the risk of skin irritation, respiratory discomfort, and systemic toxicity.
- Rinsing: After the prescribed period, rinse the hair thoroughly with lukewarm water. Remove all residue with a mild shampoo if the product label recommends it.
- Post‑treatment: Comb out dead lice and nits with a fine‑toothed lice comb. Repeat the combing process 7–10 days later to capture any newly hatched nits.
- Precautions:
- Avoid use on children under 2 years, pregnant or nursing individuals, and persons with known organophosphate sensitivity.
- Do not apply to broken or inflamed skin.
- Wear gloves during application to prevent dermal absorption.
- Ensure adequate ventilation; avoid inhaling vapors.
If any adverse reaction—such as excessive itching, burning, dizziness, or difficulty breathing—occurs during or after the exposure, wash the area immediately with soap and water and seek medical attention.
The ten‑minute exposure window balances efficacy against the potential for toxicity, aligning with regulatory recommendations and peer‑reviewed studies on organophosphate lice treatments.