There are some good shampoo products that can be purchased from the pharmacist for an itchy scalp. And the pharmacist, I have found, it always happy to help. It is worth a try before seeking further medical attention and thinking of worst scenarios.
Itching of the scalp can also be caused by dryness of the skin and dermal problems, allergies to hair products as well as fungal problems.
Nizoral shampoo can be purchased without a prescription and may be worth a try. Your pharmacist will advise if you ask him/her and will also say whether you need medical attention.
Best wishes.
You need a professional consult with a dermatologist. Itching of the scalp can have many etiologies that are quite complex. Liver disease, for example, can cause itching. Do not assume the problem can be solved by over-the-counter medications.
If you are definitely sure that there are no head lice problems, you may have an allergy either to any of your hair products or your detergents.
Head lice are not very easy to spot, but as you will already know the tell tail signs are the nits, which are like little white specks like sugar grain on a hair.
You can purchase from your pharmacy, specialist shampoo for an itchy scalp as well as head lotions for head lice.
I find that I get an extremely itchy scalp when I get rain on my head.
When you wash your hair, make sure that you rinse your hair thoroughly.
Have you had any colourant applied to your hair, either at home or at a hair salon? It may be a reaction to that.