Last two weeks my head has been soo itchy, I've tried anti dandruff shampoo and also checked for anything like nits. It's also affecting my face, especially around my jaw line and forehead. The itching is so intense it's driving me mad! No rash or anything that I can see. I do get hayfever but it's never made me itchy before. Not changed washing powder or anything like that. What can I do?