96 year old woman has itchy scalp and neck

I wonder about any new shampoo or other products that she might be using on her hair. Even if her hair products are not new, maybe a gentle or non-allergenic shampoo might help until you see the dermatologist.
With regard to all the vitamins and supplements, it might be helpful to bring those products to her next doctors appointment for feedback. Another option might be to take them to the pharmacy where you have her regular prescriptions filled for a similar review.
Best of luck.

woojr, it occurs to me that if it were the vitamins, the reaction wouldn't be limited to head an neck. Tillymack's suggestion about shampoo or hair products makes sense to me. I'd give Selsun blue a try, the one with selenium sulfide.

I have a lot of itching on the head as well and it is due to allergies, but.
Lichen planus or other skin issues.
Is there flaking or bumps in her hair and is it causing itching?
It could be an auto immune issues
Did she change shampoos, cream, rinse?
Does she use any hair gels?
For me I have a spot close to the hair line in back. That is where I itch the most.
Check every thing your mother uses. To see if any of them says new and improved.
You need to get her to a Dermatologist. I know it can be hard getting in give them a call and see if there’s anyway you could be on a waitlist or a checker. Years ago, I would be a checker and I got in much faster
I wish you and your mother the best Mothers are special

She has an appt with dermatologist next week. She's had the family doc examine her and has a prescription for an ointment that she didn't use because she bought something from a health paper she subscribes to, "Second Opinion" I believe it's called. Another fact here is she isn't always upfront about her business. In other words she lies to the doctor. She recently added to the story that she had fallen and hit her head and demanded a MRI. The fall she claims happened two weeks before the itching began but didn't tell us. We went to the doctor and she tells the doctor she doesn't want the MRI because the guy from the Second Opinion paper said the MRI might actually reveal something you don't want to know. Getting the picture here? Today she goes to her weekly visit to the hairdresser. Last night I asked her about her hair products history (for the 20th time). It's definitely a possibility that something is a problem there. Including the hair dryer time and the baking soda she adds to the shampoo because she says it makes her hair thicker. My wife says it can cause drying her scalp. As far as the location of the itching. My Googling seems to indicate these symptoms can pop up in the same place at random times. Also she has some bumps on her neck. They're like a couple inches long, 1/4 inch wide that look and feel like a callus and have matching color with her skin tone. They itch with the scalp at the same time. In short, she not very cooperative, gets ideas from vitamin peddlers which she's been buying from for 50 years or more. Fortunately her computer burned out so she can't search all the information that says she might have cancer. This year I've had her to the eye doctor when she believed she had macular degeneration. We spent an hour with him showing her that her eyes were fine. We got back to her house and I found vitamin peddlers selling pills for eyes. I have the printout from the eye drs taped up with all the info on macular degeneration. The itching is real. She lives alone but has company and I see almost everyday. My wife thinks she's having an anxiety attack because she no longer has the computer to occupy her time. That would be a simple fix except this past six weeks or so has been wonderful without the computer. She has been scammed so many times for thousands of dollars and has had credit card problems from fraud. She forgets she buys things then makes claims to get her money refunded. This has been going on before I got involved with POA duties. I could go on for hours about the scams alone. I just can't get her to stop taking the vitamins for a week to see if it matters at all. She's amazing how she keeps clean, cooks healthy and enjoys sports (Eagles & Phillies), goes to PT and entertains the people there. Sorry getting carried away, LOL. Thank you for your time and caring. And yes, mothers are very special and she gets a lot of love from our kids as well.

So sorry you have your hands full. You stated she get her hair fix once a week. Talk to her hairdresser. Ask if they notice things, and ask if they have changed brands of shampoo.
Wish you the very best.

I spoke to mom last night and she told me she stopped using baking soda on her hair yesterday. This is truly a good thing. I'll be seeing her either tonight or tomorrow, depends on the weather. Baking soda really dries her scalp.