Welcome to HCM,
Your son might have some infection on the scalp like dermatitis
or fungal infection
He might have some allergy to some oil,shampoo etc which may cause itching and giving rise to infection like folliculitis
Go for antibiotic medicines and find out cause and go for treatment accordingly.
Use branded shampoo.hair oil containing vit E.
Wash his hairs regularly and do not keep hair wet for more time.
oK AND BYE.