our family friend suffers from it in patches. stress can set off episodes, as can sweat, or not maintaining a strict habit of keeping skin oil and grease free. Some seasons are worse for it.

Ketocanozle cream is effective https://www.nhs.uk/medicines/ketoconazole/#:~:text=Ketoconazole%20is%20an%20antifungal%20medicine,athlete's%20foot

more resources--copy paste to address bar

face--https://www.amazon.com/s?k=CeraVe+RETINOL+Cream+Serum+for+Face+with+niacinamide%2C&crid=1F3ZVZUDTUNR3&sprefix=cerave+retinol+cream+serum+for+face+with+niacinamide%2C%2Caps%2C102&ref=nb_sb_nos

https://www.mayoclinic.org/diseases-conditions/seborrheic-dermatitis/diagnosis-treatment/drc-20352714#:~:text=First%20try%20a%20mild%20corticosteroid,you're%20treating%20the%20condition.

https://www.aafp.org/pubs/afp/issues/2015/0201/p185.html#:~:text=The%20mainstays%20of%20treatment%20for,effective%20as%20hydrocortisone%201%25%20cream.&text=Ketoconazole%202%25%20gel%20(Xolegel),scaling%20compared%20with%20vehicle%20alone.

I've had it for about 20 years. It started in my ears and on my neck behind my right ear and in the last few years on my forehead and face. I thought it was just something old people got but I had a 26-year-old roommate who had it on the back of her neck like alligator skin. A few months ago I finally found something that really works. It doesn't heal it but it makes it go away. It's from dermgentle.com. i don't know if you can get it in Britain, but it's worth trying! Good luck!

My husband got this on his head after a head injury. We assumed it was due to stress also. Scaly yellow skin. He was prescribed coal tar shampoo but I didn't use it coz of side effects/risks. I exfoliated scales then made up cream from coconut oil, crushed aspirin and cinnamon.
Rubbed in daily. Cleared up no problem 👍

Have you tried petroleum jelly or hydrogen peroxide,the 3% kind?

Stress has a lot to do with it....practice deep abdominal breathing!

Black seed oil taken over time may help. There have been over 400 medical research studies done on it. Good
For everyone except pregnant women

My mom makes a washed ghee. It does wonders for many skin issues, including eczema….maybe you could try that?
Just make sure you find one that is pure and organic. Not filled with scents or other crap which will irritate further