What is a common feature of seborrheic dermatitis?

Seborrheic dermatitis is characterized by the presence of greasy scales, which is a hallmark feature of this condition. This skin disorder primarily affects oily areas of the body, such as the scalp, face, and upper back. The excess oil production contributes to the buildup of skin cells, leading to the formation of thick, yellowish, greasy scales that may be associated with inflammation.

In contrast, a dry and flaky scalp is more indicative of conditions like dandruff, which is distinct from seborrheic dermatitis. Itchy welts typically point to conditions like hives or allergic reactions rather than dermatitis. Red patches can occur in various conditions, including psoriasis or eczema, but the greasy nature of the scales in seborrheic dermatitis is what sets it apart. Thus, greasy scales are a defining characteristic of seborrheic dermatitis, linking them directly to the condition's pathology.