How can you tell that lice have been eliminated?

How can you tell that lice have been eliminated? - briefly

A thorough inspection with a fine-tooth comb showing no live insects or viable nits for several days confirms eradication. Re‑examination after a week, with no new eggs emerging, validates that the infestation has been eliminated.

How can you tell that lice have been eliminated? - in detail

After treatment, the primary indicator of success is the absence of live insects. Examine the scalp and hair with a fine‑tooth lice comb; the comb should come away clean, without crawling lice or moving debris. Perform this inspection daily for at least a week, then every other day for an additional two weeks.

A secondary sign is the elimination of viable eggs. Viable nits are attached within ¼ inch (6 mm) of the scalp and are typically oval, white, and firmly glued to hair shafts. If only empty shells or nits located more than ¼ inch from the scalp remain, the infestation has likely been resolved, because these are no longer viable.

Third, the itching sensation should subside. Persistent pruritus beyond 10 days after the last application of treatment suggests remaining lice or a secondary skin reaction. Absence of new itching episodes supports eradication.

Finally, conduct a follow‑up check of personal items and the living environment. Wash bedding, clothing, and hats in hot water (≥130 °F/54 °C) or seal them in plastic bags for two weeks. Clean combs, brushes, and hair accessories with hot, soapy water. If no lice are found on the individual and no re‑infestation appears after these environmental measures, the problem can be considered eliminated.