@nony - I’ve never had anything like this condition. I did, however, spend a day at the beach once without applying lotion to my scalp. I applied it to the rest of my body, but not to my scalp, and I am half bald.
I got burned so bad that it appeared I had all the conditions of scalp dermatitis. There was the redness, peeling and flaking skin, and that petulant itch. Some people actually thought I had the disease when I returned back to work but I had to explain that it was sunburn.
It’s hard to cover that stuff up when it’s on your scalp, so I understand how these people must feel.