Mother is abusing her face. Any ideas?

It is called excoriation disorder, as well as other names.
Here is an article on this forum:
"Compulsive Skin Picking in the Elderly".

Oh yes-
that is a dementia thing
-try to cut and file nails
apply antibiotic cream
-bandaids
yes it’s awful to go out w bandaids on face but they help a bit w a barrier
-I don’t know what else

I have had an ongoing battle with this picking disorder with my DH Aunt, 93 with dementia. 
She started this several years ago. First on her arms, then her face, then the rim of her ears. One particularly bad place on top of her nose made her doctor think it might be skin cancer. It wasn’t. We tried salves and allergy meds. Covered the places with little round bandaids that she would then peel off. We would try to catch her and discourage her. Once I showed her in a mirror what she was doing to her face. She started crying and said “I don’t want to do that to myself”. I decided then not to mention it again. I would overhear her tell her HH nurse that she knew she shouldn’t do it. I felt she couldn’t help it and anything I said would make her feel worse. 
Then my cousin shared how she had started giving her mom CBD oil. Her mom has Parkinson’s and has been placed on hospice. She was no longer verbal, walked with the Parkinson’s shuffle and had the Parkinson’s mask. My cousin decided to try CBD oil herself and then gave it to her mom. The changes were amazing. Her mom began to speak. Would say she needed to go to the bathroom. Started walking normally, would smile. She was always a very pleasant, well loved person and everyone was so happy to have her “back”. Since I was having back pain, I decided to start taking the oil. It helped me (right away) so I decided to give it to my DH aunt. I did not even think about the picking. I was giving it to her to see if it would affect her anxiety, memory. or her incontinence. To see if it could be a therapeutic remedy for her. Then one day I realized that I hadn’t seen any current scabs or sores. 
(I don’t live with her but saw her weekly). So when I saw her next, I realized that she had stopped picking. She continued to take the oil until it was gone. I decided to see what would happen. It’s been about four months now and she has one place back on the rim of her ear. So I will start it again. 
Here are two links on this disorder. The first one doesn’t include any mention of the elderly or dementia.
The second one lists many drugs that have been tried. One is for epilepsy patients. That was interesting to me because CBD has been used to make an epilepsy drug approved by the FDA. 
The condition has been around for a long time.
Good luck and let us know if you find a solution that works for your mom. 

https://www.mhanational.org/conditions/excoriation-disorder-skin-picking-or-dermatillomania


https://en.m.wikipedia.org/wiki/Excoriation_disorder

Medications for anxiety might help.
I would avoid ORAL Benedryl or other medication like that. It can make your "brain foggy" and for someone with dementia that is the last thing they need. (my Husband had allergies and I used to give him Benedryl and after taking it 1 time myself and having that foggy brain feeling I did not give it to him any more) Topical Benedryl does not do the same thing.
Mittens ("old fashioned type" cotton if you can find them) would prevent more damage and keep them on all day if needed. If she removes them I wold use one of the clips that keep kids gloves attached to the coat. Clip to a PJ sleeve. Mittens would keep the fingers from individually scratching.
If you can't find mittens I would try sewing a sock to the end of the sleeve this would encase the had to prevent the scratching.

Did the dermatologist run any tests for allergies?  Or suggest using chemical free soaps and lotions?    And, in fact, does she use commercial lotions and soaps for cleaning?  

If you don't line dry clothes, do you use dryer sheets?   Do some research on these and you'll see how toxic they are.

Maybe she’s allergic to a pet in her house or in yours

Try changing your laundry soap . Try using something free and clear Or for babies . No wool blankets

I know that certain pain meds make a nose itch . Ask her doctor if you could use children's or regular Benadryl . And count your blessings ...... It ERKS me to hear you complain about your sleep being disturbed when she’s the one itching. Good luck

OMG, yes! My now deceased aunt had dementia and did this. Constantly picked her face, head and arms. She was always a bloody, scabby mess. Best thing you can do is keep her nails short, short, and have her wearing long sleeves. Keep lotion on her skin and keep her hydrated. Not sure you can do anything beyond that. It is very frustrating!

My mom stares in a makeup mirror for an hour or more picking at her face. She makes all kinds of marks and places on her face. I like you have tried everything. But as you know when you tell them anything it’s gone in a few minutes. I hope we can find a solution. I had wondered if anyone else was having this issue.

Have you tried any anti anxiety medications?

My son has severe autism and has a few “ticks” as I call them - that is the same type of compulsive behavior. For instance - he runs his hand through his hair, pulling at it - at a frantic pace. He has thick beautiful hair but this tick has created a bald patch on the top of his head at times. Frustrating! My only solution has been to keep his hair in a crew cut - which I hate. He also chews on his fingers to the point of creating blood blisters. His hands are an awful scarred up mess and I know what you mean about the worry that others might think that abuse is at play. Since having his teeth or fingers removed isn’t an option - it’s a whole lot of “Rainman, take your fingers out of your mouth” - over and over and over again. I don’t like the idea of medication and in his case I don’t think it would help as it’s a self stimulating behavior rather than an anxiety related one.

Anyhoo - long story short - I completely understand your frustration. Big help, huh?

There is always redirection - have you tried anything like one of those “busy blankets” or giving her a pile of things to fold? And - maybe a prescription for anxiety meds for night time?

Hopefully - someone else will come along with a better suggestion but in the mean time - at least know that you’re not alone.

This sort of picking that becomes compulsive is not unusual in the elderly or the mentally ill. She may need a very mild anti-depressant. If the dermatologist is not familiar with this compulsive picking at face and scalp it makes me think not too special a dermatologist. If you google this you will see instances of it; it becomes almost like the hair pulling thing, and I wish I could remember the names for this compulsive picking, but too long out of nursing and I can't! Pursue this. Others have mentioned this on the forum, and in fact one person thought CBD oil helped her elder. I hope they will see your note and respond. Keep at your doc about this one. Don't take "normal" or "will go away" for an answer.