If you've treated your child for head lice more than once this term and they still have it or it's come straight back within a few weeks, you're not doing anything wrong. But something in the process usually needs adjusting. Recurring head lice almost always comes down to one of a handful of specific, fixable causes which we will talk cover in this article.

A missed egg, not a failed treatment

Even a careful, thorough comb can occasionally miss a single egg, especially in thick or long hair. That egg hatches within 5 to 10 days, and within another 1 to 2 weeks the newly hatched louse matures and starts laying eggs of its own. To a parent, this looks exactly like the original infestation “coming back” but it's actually the tail end of the first one, quietly continuing. This is exactly why a follow-up comb 5–7 days after the initial treatment matters so much. Skipping it is one of the most common reasons lice seem to keep returning.

Re-infestation from an untreated contact

Head lice spread through direct head-to-head contact, and they don't respect a household boundary. If your child is back in class, at sport, or on a playdate with someone who still has an active, untreated case, they can pick lice up again almost immediately through no fault of your treatment at all. This is also why checking every member of your own household matters: if one person is treated and another isn't, lice can simply move between family members and appear to “return” to the person who was already cleared.

Sending your child to school before treatment is complete

This is one of the most common and most avoidable; reasons head lice keeps circulating. School is exactly the kind of environment where head-to-head contact happens constantly: at the reading corner, on the bus, during sport, in a group photo. If a child goes to school with untreated head lice, even for a single day, they can pass it on to a classmate and that classmate can just as easily pass it straight back later, once their own case has run its course. It becomes a cycle that keeps circling back through the same friend group, sometimes for months. The simplest way to break that cycle from your end is straightforward: don't send your child back to school until treatment has started and the hair has been properly combed through.

Skipping the basic household cleaning steps

You don't need to clean your entire house from top to bottom, but a few basic steps do matter, and skipping them can contribute to lice seeming to return. Wash pillowcases, sheets, and any clothing worn in the last day or two on a hot cycle, and give hairbrushes and combs a proper clean - either hot water or 24 hours in the freezer. These steps won't eliminate a case on their own, but combined with a thorough comb and a follow-up treatment, they close off the small number of ways lice can reappear from recent contact points.

Chemical treatment resistance

Many pharmacy treatments rely on insecticide-based chemicals to kill live lice. Over time and repeated use, some lice populations have developed resistance to these chemicals, meaning a treatment that worked well a few years ago may be far less effective today - killing some lice but leaving others, including most eggs, untouched. Physical combing doesn't rely on chemistry to work, so it isn't affected by resistance in the same way.

Not repeating the treatment at the right time

Whichever method you use, a single treatment usually isn't the full story. Eggs that survive the first round need a second pass once they've hatched before they mature enough to lay their own eggs. Without that second round, the cycle simply resets itself.

Long or thick hair making it harder to catch everything

The more hair there is to work through, the easier it is for a single egg or louse to be missed in any one pass not because of poor technique, but simply because there's more ground to cover thoroughly. This is one of the reasons a slow, systematic, section-by-section approach matters more than speed.

When it's time to bring in a professional

If you've been through more than one or two rounds of home treatment and it still isn't resolving, that's not a sign you've failed; it's usually just a sign the case needs a more thorough, trained pass. A professional treatment removes the guesswork around technique, timing, and follow-up, and checks the whole household properly in one visit.

Frequently asked questions

Why does my child keep getting head lice?

Usually one of a few causes: a missed egg from the first treatment, re-infestation from an untreated contact, or treatment resistance to a chemical product.

Can head lice become resistant to treatment?

Yes, resistance to certain chemical treatments has become increasingly common, which is part of why physical combing methods are considered more reliable.

How many times do I need to treat head lice before it's fully gone?

Most cases need at least two rounds an initial treatment and a follow-up 5–7 days later to fully break the cycle.

Is it normal for head lice to come back after treatment?

It's common, and it doesn't mean the treatment failed. It usually reflects either a missed egg or new exposure from close contact with someone else who has lice.

Should I send my child to school if they still have head lice?

We'd recommend against it. Sending an untreated child to school risks spreading lice to classmates, who can just as easily pass it back later - keeping the cycle going within the same friend group.

Tired of the cycle repeating?

If you've been going round and round with head lice and it isn't resolving, a thorough professional treatment can break the cycle properly. [Book now] and we'll take care of the rest.

How to make a booking with No Nits?

The best and most effective technique to stop the cycle of nits can be found here. If you are lucky enough to live within one of these suburbs you can book a No Nits service today. If you cannot see you suburb, feel free to reach out to us for a custom quote.