Yesterday and today I used my husband's store brand dandruff shampoo. It was near the bottom of the bottle and what pumped out was marbled in color. Generic Head and Shoulders.
I had noticed a minor itch yesterday after a long phone call for business and holding the phone on that ear. Today the back of the ear and skin extending into hairline at the upper ear was red and very itchy.
I showed it to my doctor and he thinks I didn't rinse the shampoo well either yesterday or even both days and reacted to it. He gave me Hydrocortisone 2.5% to use 2 or 3 times a day for a few days. I've used it once and it's already much less red but still very itchy. No bumps, swelling, fever, other concerns. I'm almost 64 and female, allergic to nickle and sulfa drugs, CT iodine.
My dermatologist told me last year that the flaky forehead is seborrhea and gave me a wash for that. I can't tell that it's really helped. I'm not due to see him for another month.
Sound like an allergic reaction to you maybe triggered by the heat from the cordless phone for over an hour?