What is a common characteristic of seborrheic dermatitis?

Seborrheic dermatitis is primarily characterized by redness and scaling of the skin. This condition often presents as inflamed patches that may be greasy and covered with white or yellowish scales, typically appearing on the scalp, face, and sometimes on the body. The inflammation leads to a red appearance, while the presence of scales results from the excessive buildup of skin cells. This combination of redness and scaling is crucial in diagnosing seborrheic dermatitis.

Other options describe conditions that do not align with the characteristics of seborrheic dermatitis. An oily scalp may occur but it is not limited to that region nor is it the defining feature; formation of blisters is associated with different skin disorders, and cold sores are specifically related to herpes simplex virus infections, which are unrelated to seborrheic dermatitis.