If you have seen head lice or nits in your child’s hair, the first job is finding live lice. The NHS says the only way to be sure is finding live lice with a fine-toothed detection comb, and recommends “wet combing” with conditioner on days 1, 5, 9 and 13, then checking again on day 17. There is no need to keep your child off school. This sets out the NHS page “Head lice and nits”.
1. Only live lice confirm it. Use a detection comb.
2. Wet combing on days 1, 5, 9 and 13, check on day 17. A schedule to catch newly hatched lice.
3. No need to miss school. There is nothing you can do to prevent head lice, the page says.
Wet combing — the NHS steps
| Step | What the NHS says | Worth noting (our gloss) |
|---|---|---|
| 1. Wash | Shampoo as usual, then use plenty of conditioner | Hair stays wet |
| 2. Comb | Comb the whole head with the detection comb from the roots to the ends | The whole head, no gaps |
| 3. Again | When finished, comb the whole head a second time | Catch what was missed |
| 4. Repeat | Wet comb on days 1, 5, 9 and 13 | Every 4 days |
| 5. Check | Check again on day 17 that everyone’s hair is clear | The whole family |
The NHS says days 1, 5, 9 and 13 are to catch newly hatched lice. “Every 4 days” is our arithmetic from the dates.
If you use lotions or sprays
Lotions and sprays are sold in pharmacies, supermarkets and online, and some need repeating after a week to kill newly hatched lice. Check the pack for safety information and instructions.
Not recommended — unlikely to work
- Products containing permethrin
- Head lice “repellents”
- Electric combs for head lice
- Plant oil treatments such as tea tree, eucalyptus and lavender oil, and herbal remedies
The NHS says these are not recommended because they are unlikely to work.
School and prevention
| Question | The NHS answer | Worth noting (our gloss) |
|---|---|---|
| Keep them off school? | No need | UK guidance — check your school too |
| Can it be prevented? | Nothing you can do | The official answer is no |
| Limiting spread | Regular wet combing with a detection comb | Finding them is how you limit them |
| Medicine as prevention | Don’t — it can irritate the scalp | Only when there are lice |
An itchy scalp with white flakes may be dandruff — see choosing a dandruff shampoo.
Facts the US CDC adds
The US Centers for Disease Control and Prevention adds some figures. Adult lice are about the size of a sesame seed and move by crawling; they cannot hop or fly. The most common way to get them is head-to-head contact with someone who has them; sharing clothing, combs or bedding is less common. Lice that fall off and cannot feed die within two days, and nits take about a week (6 to 9 days) to hatch. They are most common in preschool and elementary-school-age children and their households, and do not transmit disease, so they are not considered a health hazard.
Read alongside the CDC’s 6 to 9 day hatching time, the NHS schedule of days 1, 5, 9 and 13 makes sense as a way to catch newly hatched lice (our reading).
Checklist
- ☐ Look for live lice with a detection comb
- ☐ Conditioner, then comb roots to ends, and once more
- ☐ Wet comb on days 1, 5, 9 and 13; check everyone on day 17
- ☐ With lotions, follow the pack and check whether a second dose is needed after a week
- ☐ Don’t use medicine to prevent lice
Questions that remain
Should I wash pillows and clothes?
The NHS page read here does not cover washing bedding or clothes, so we say nothing about it.
What about Korean schools?
We did not read Korean education offices’ or schools’ attendance rules; check with your school. Children’s daily activity is in children’s physical activity.
Sources
- NHS — Head lice and nits — original (page last reviewed 22 April 2024, next review due 22 April 2027; checked 12 October 2026). Live lice, detection comb, conditioner, roots to ends and a second time, days 1, 5, 9, 13 and 17, lotions repeated after a week, four treatments not recommended, school, no prevention, no medicine as prevention.
- CDC — About Head Lice — original (last reviewed 4 June 2024; checked 12 October 2026). Sesame-seed size, crawling, head-to-head contact, two days, 6 to 9 days, no disease.
- Not read. Korean agencies’ head lice guidance; Korean school attendance rules.
- Added by us. The “worth noting” column and the 4-day arithmetic.
Where to check further
- A pharmacy — detection combs and head lice lotions.
- Your child’s school — attendance policy.
Written 12 October 2026. The content follows the NHS and CDC originals; the glosses are ours.