Hello ladies! We had this problem a few months ago and a friend suggested using a natural concoction, which worked both on my daughter and me (it's much nicer smelling than the store-bought chemicals and you only have to put it in your hair for one hour, three times a week, instead of overnight; also extremely gentle). I tried this on myself and the little buggers were gone immediately. I used the horrible chemical junk on my daughter (since that was what I had on hand at the time) and she got reinfested twice after that!! I waited a few hours for a friend to buy & bring the essential oils to me (shuddering all the while at the thought of those things in my hair!!!!) Here's the mixture of essential oils:
20-25 drops rosemary*
20-25 drops eucalyptus
20-25 drops geranium
mixed into 100 ml of olive or other light oil (or you can mix half oil/half warm water).
*Don't use rosemary if you're expecting; instead use cedarwood (which is also great for dandruff)
Lean over a sink and rub through hair, all the way to the ends, and leave on for an hour. Be careful not to get it in your eyes, as with any shampoo. I wrapped some plastic wrap & a towel around our heads to keep from dripping. Wash out a couple of times at least, with shampoo. This also conditions your hair and you smell lovely, not all chemically. This recipe is for an adult head, so for a child you could probably half it, depending on hair length. I found that it made my hair slightly oily, but with another quick wash in the morning and was fine, and didn't have to miss a day of work because of that awful smell.