Hello,
It sounds like seborrheic dermatitis.
Seborrheic dermatitis is a common skin condition that causes flaky,dry, white
to yellowish scales
to form on oily areas esp under the nose or anywhere on face. You can treat flaking and dryness with over-the-counter dandruff or medicated shampoos. Shampoo the hair vigorously and frequently (preferably daily). Active ingredients in these shampoos include salicylic acid, coal tar, zinc, resorcin, ketoconazole, or selenium.