what causes seborrheic dermatitis
Doctors don't yet know the exact cause of seborrheic dermatitis. But it may be related to: 1  A yeast (fungus) called malassezia that is in the oil secretion on the skin. 2  An inflammatory response related to psoriasis. 3  The season, with episodes tending to be worse in early spring and winter.4  Symptoms.5  Risk factors.octors don't yet know the exact cause of seborrheic dermatitis. But it may be related to: 1  A yeast (fungus) called malassezia that is in the oil secretion on the skin. 2  An inflammatory response related to psoriasis. 3  The season, with episodes tending to be worse in early spring and winter. 4  Symptoms. 5  Risk factors.