How to know that lice are gone? - briefly
Inspect the scalp and hair several days after treatment; if no live lice, no attached nits within a centimeter of the hair root, and no itching persists for a week, the infestation is eliminated.
How to know that lice are gone? - in detail
Determining that head‑lice infestation has been eradicated requires systematic observation and verification. The following criteria confirm successful treatment:
- No live insects are found on the scalp, hair shafts, or clothing after a thorough inspection.
- All eggs (nits) have been removed or have hatched and are no longer attached to the hair strands.
- The scalp shows no signs of irritation, redness, or itching that persist beyond the normal healing period.
- Re‑examination after 7–10 days, when any surviving nits would have hatched, reveals no new nymphs or adult lice.
To perform the verification, follow these steps:
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Visual inspection
Use a fine‑toothed comb on wet, conditioned hair. Separate sections and examine each strand under good lighting. Look for live insects, which are brown or gray, and for nits, which appear as tiny, oval, yellow‑brown shells attached close to the scalp. -
Physical removal
If any nits or lice are detected, pull them out with the comb. Continue combing each section multiple times to ensure complete removal. -
Repeat examination
Conduct a second inspection 7 days after the initial treatment. This interval allows any remaining eggs to hatch; newly emerged nymphs will be visible if treatment failed. -
Follow‑up check
Perform a final assessment 14 days after the first inspection. Absence of live insects and nits at this stage confirms that the infestation has been fully cleared.
Additional verification measures include:
- Environmental sweep – Wash bedding, hats, and scarves in hot water (≥130 °F) or place them in a sealed bag for two weeks to prevent reinfestation.
- Family screening – Examine all close contacts; untreated carriers can reintroduce lice.
When all listed conditions are satisfied, confidence in the complete elimination of the infestation is justified. Continuous monitoring for a few weeks remains prudent, but the absence of live lice and viable nits after the described timeline indicates that the problem has been resolved.