What type of skin disorder is characterized by the presence of excess oiliness?

Seborrhea is characterized by excess oiliness, particularly affecting the scalp and other areas where sebaceous (oil) glands are active. This condition leads to an overproduction of sebum, resulting in greasy skin and hair. It can also cause flaking, which may be observed as dandruff when it occurs on the scalp. The condition may present with additional symptoms such as irritation or redness, but the defining feature is the increased oiliness. This differentiates seborrhea from other skin disorders listed.

Psoriasis, dermatitis, and rosacea involve inflammation but do not primarily present with excess oiliness; instead, they manifest with other symptoms such as redness, scaling, or pustules. Understanding these characteristics is crucial for identifying and treating skin disorders effectively.