Hello,
Seborrheic dermatitis causes flaky,dry, white to yellowish scales to form
on oily areas esp under the nose or anywhere
on face. People with
seborrheic dermatitis produce too much sebum (the natural skin oil). Later, pityrosporum yeast grows excessively in the sebum, sometime along with bacteria, making the dermatitis more persistent.
Topical antifungals and mild steroids are the usual treatment and combination of the two can be used to treat stubborn patches.