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‘Help, my kids keep getting head lice!’ Here’s how to break the cycle of nits

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14th June, 2023

Wrangling head lice, and the children they infest, must be up there with the most challenging duties a parent or carer has to face.

Pri­ma­ry school-aged chil­dren, who seem to always be in close prox­im­i­ty to one anoth­er, are the most sus­cep­ti­ble to lice.

But by exploit­ing the screen-shar­ing and self­ie-tak­ing habits of tweens and teens, these lit­tle par­a­sites are find­ing more ways to spread.

And they’re no eas­i­er to kill off.

What are head lice and nits?

Head lice, known by their sci­en­tif­ic name Pedicu­lus humanus capi­tis, are tiny insects that are only found among the hair on a human’s head. They’re not found any­where else on the planet.

They scut­tle up and down shafts of hair. They have per­fect­ly designed claws, that look a lit­tle like cara­bin­ers, allow­ing them to move about how a rock climber uses guide ropes. They’re agile on our hair, but clum­sy once they’re off.

They don’t jump or fly. They move from head to head through direct phys­i­cal contact.

Our hair is their home but our blood is their food. Head lice feed on the scalp and have spe­cial­ly designed mouth-parts to suck out blood up to a half dozen times a day. It means child with an aver­age sized infes­ta­tion of head lice may give up less than 0.01 ml of blood per day.

When it comes time to lay eggs, that we affec­tion­ate­ly refer to as “nits”, the lice don’t want the more than 100 or so eggs they can pro­duce in a lifes­pan just rolling off our heads. They “cement” their eggs to the shafts of hair. It’s some of the best “super­glue” you can find!

Once laid, the eggs will hatch with­in a few days. With­in a week, the lice are ready to lay more eggs. The adult lice can live for up to a month if con­di­tions are right.

My child has head lice, should I be worried?

While close­ly relat­ed lice have been impli­cat­ed in the spread of some of the most dan­ger­ous and dead­ly pathogens to human health, head lice are much more benign. They’re annoy­ing but won’t make us sick.

Their bites may cause an itchy irri­ta­tion to our skin. Our bod­ies react to the sali­va they inject when they bite. In the same way we all vary in our reac­tion to mos­qui­to bites, the same dif­fer­ences result from lice bites. Some peo­ple will hard­ly notice them, oth­ers will be dri­ven wild with itchiness.

Health author­i­ties in Aus­tralia do not con­sid­er head lice a risk of trans­mit­ting pathogens that are harm­ful to humans.

There is no doubt they’re annoy­ing but per­haps the great­est health threat of head lice is to the health and well-being of par­ents respon­si­ble for their eradication.

Do we really need chemicals?

“Just kill them all, what­ev­er it takes” is a com­mon refrain among those try­ing to rid their chil­dren of the lat­est round of infestation.

There is a wide range of prod­ucts avail­able at your local phar­ma­cy to treat head lice. These prod­ucts should be reg­is­tered with the Ther­a­peu­tic Goods Admin­is­tra­tion and be assessed as both safe and effec­tive to use. Most of these prod­ucts are insec­ti­cides that kill the lice on contact.

How­ev­er, evi­dence seems to be mount­ing that some of these insec­ti­cides aren’t work­ing as well as they once did. Resis­tance in head lice to com­mon­ly used prod­ucts may be the result of their exces­sive or incor­rect use. The more lice that escape a treat­ment, the greater the chances of them devel­op­ing resis­tance in much the same way bac­te­ria are devel­op­ing tol­er­ance and resis­tance to com­mon­ly used antibi­otics.

Head lice are still sus­cep­ti­ble to alter­na­tive approach­es. Prod­ucts derived from Aus­tralian plants, such as tea tree or euca­lyp­tus, may be bet­ter than insec­ti­cides. But these are still chemicals.

All these prod­ucts should be used in accor­dance with the direc­tions for safe use.

A range of prod­ucts are mar­ket­ed as “repelling” head lice. But there is lit­tle evi­dence these are a reli­able way to avoid pick­ing up head lice from your friends or family.

Is there a chemical-free approach?

A strong rec­om­men­da­tion by health author­i­ties in Aus­tralia is to skip the sprays, creams, and lotions and embrace the “con­di­tion­er and comb” or “wet comb” method and phys­i­cal­ly remove the lice.

This is not just good advice for those not want­i­ng to avoid chem­i­cals, it over­comes hav­ing to deal with insec­ti­cide-resis­tant lice.

The steps in this process are rel­a­tive­ly straight forward.

To immo­bilise the lice, apply hair con­di­tion­er to the child’s damp hair. Then use a fine toothed “lice comb” to sys­tem­at­i­cal­ly work through the hair and remove adult lice. Reg­u­lar­ly wip­ing the comb on tis­sues or paper tow­el will reveal the dis­patched lice.

This approach works but must be repeat­ed twice, about a week apart, to break the life cycle of the head lice.

Head lice eggs are less sus­cep­ti­ble to treat­ment, no mat­ter what treat­ment you choose. As all the eggs will hatch with­in a week or so, repeat­ing treat­ments again and tar­get­ing the adult lice before a new batch of eggs is laid will pro­vide the best results.

The secret to effec­tive erad­i­ca­tion of the infes­ta­tions is patience and per­sis­tence. Per­haps a new prac­tice in mind­ful­ness?

Will our household ever be free of them?

Head lice are a nor­mal part of life for young chil­dren. It doesn’t mat­ter how clean and tidy your house is, you’ll inevitably have to deal with an infestation.

Fre­quent wash­ing of bed sheets, tow­els, and vac­u­um­ing floors won’t keep them away. Head lice don’t sur­vive long out of our hair so you’re unlike­ly to pick them up from car­pet, fur­ni­ture, or even shar­ing hats. They don’t float around in swim­ming pools either.

If a child has per­sis­tent infes­ta­tions and has an adverse reac­tion to the head lice, con­sult your local health pro­fes­sion­al. There are some alter­na­tive options, includ­ing some med­ica­tions, that may also assist in reduc­ing the bite reac­tions as well as the infes­ta­tion itself.The Conversation


Cameron Webb, Clin­i­cal Asso­ciate Pro­fes­sor and Prin­ci­pal Hos­pi­tal Sci­en­tist, Uni­ver­si­ty of Sydney

This arti­cle is repub­lished from The Con­ver­sa­tion under a Cre­ative Com­mons license. Read the orig­i­nal arti­cle.


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