Thanks for the query,
First we should think of the scalp
infection like seborrhic dermatitis
. clear all this by some antifungal shampoo, Secondly Pediculosis
(lice) is very common infection apply some permethrin cream
and also shave . to clear this type infestation. and lastly some antibiotic like (cephlexin)should also be used to get rid of superadded infection.
I hope this three way approach will cure this chronic condition of your child