jcather mentioned patch testing for Allergic Contact Dermatitis, ACD for your itchy scalp. Our scalp is very sensitive to our grooming products. Google the 5 4 or 5 Day Extended Patch test. ACD is a form of eczema an auto-immune disease. Like me those of us with auto-immune diseases often have several auto-immune diseases. It is possible your hair products are causing this reaction. Hair products are loaded with chemical and yes even natural ingredients (like tea tree oil, aloe vera,tea tree oil, essential oils which can cause reactions). Natural doesn't mean safe. Preservative additives are an allergy for many, like MI/MCI. Many manufacturers took out formaldehyde and put in MI/MCI a decade ago and now many of us are getting the MI/MCI allergy, like me. Why does a bottle of shampoo need to last 100 years? Before testing quit using any of your hair products. Wash your hair with Grandma's bar soap, only 2 ingredients- lard and lye and the lye is converted into glycerin, both are moisturizing. Grandma's is no a Mayo SkinSafe product. Yet without soft water it may be hard to get a lather. For a safe de-tangler, rub a few drops of glycerin on your hands and pat your wet hair before combing out. The safest good shampoo I have found is Clark Wash for hair and body by VMV. Yet is has more than 2 ingredients, but none cause a reaction for me. Start by looking up and studying all the ingredients in your shampoo. Even Free and Clear, touted to be an safe shampoo for ACD suffers makes my scalp itch. Once tested you will be registered on the CAMP list which filters your allergens with grooming and cleaning products and keeps updated yearly with new products. It will offer over 20 pages of products free of your allergens.I used to pull on my hair while watching TV in the evening and my husband would warn me I would go bald, yet it would relieve the itching for a few seconds. I had neurological testing, brain scans, believing the insane tingling and itching in my scalp was based on nerve damage from another health issue I had. Not the case, it was ACD.