Seborrheic Dermatitis mostly occur on your scalp, eyebrows, beard, mustache, or any hairy part of your body. It has patches of greasy skin covered with flaky white or yellow scales or crust. Skin may experience redness, possibly stinging or itching at the same time. Visit this site http://blog.drsundardas.com/category/allergies/ to view more about skin allergies and skin condition.