I've used dry shampoo twice a week for the last 5 years or so. Over the last few weeks I've developed a horribly itchy lumpy scalp. Its definitely not nits (if only it were) I haven't used the dry shampoo since but hadn't thought of it as a cause until chatting to a friend last week. I'm just wondering if anyone else has had a similar problem and what can I do to relieve it?