What Does Extremely Itchy Scalp In A Teenager Suggest?

I ll try but your site keeps closing. I have a 15 year old who appears to have folleculitis (I had as a teen) but doctor prescribed wash, cream did not help and he didn t think much of it but I (mom) do see little red dots. 15 year old (girl) refuses to stop shaving so that I know does not help, but now for few weeks she has very itchy scalp. I have looked for lice (which unfortunately she had at 5 and I know what to look for) but there is none of the telltale signs and I see abolutely nothing (looked extensively). She tried dandruff shampoo which helped a little. She s losing sleep and pretty cranky (but that could be because she s 15, who knows) There is no drug use (I m a stay at home mom and around her and her friends a lot). There is and has never been any boyfriend so there is no chance of any contact (very pretty but too smart and snarky for teen boys). She has a decent diet because my kids eat what I serve and don t get a choice and we try to eat clean bla bla, have a balanced diet with fruit and veggies. Overall she s the picture of health and active. Just really itchy, I m at a loss....