Hairdresser mentioned when cutting my hair that I have a patch of dry scalp. I had forgotten that he had said it about 3 months ago when I previously got my hair done but I'm a suspicious sort so ignored it on the basis of having no intention of buying a "special shampoo". I've never had it or any skin issues before. Could it be a new shampoo causing it? I usually use the kids anti nit tea tree shampoo from aldi, no conditioner or products, sometimes blow dry. I don't wash my hair every day, maybe 3 times per week, but I do usually wet it in the shower in the morning. Do I need a different shampoo?