Which skin condition is characterized by excessive oiliness and clogged pores?

The skin condition characterized by excessive oiliness and clogged pores is acne. Acne occurs when hair follicles become clogged with oil and dead skin cells, leading to the formation of pimples, blackheads, and cysts. This condition is often influenced by hormonal changes that increase oil production in the skin, and it can affect individuals at various stages of life, though it is most commonly seen in teenagers and young adults.

The presence of excess oil on the skin, combined with the buildup of dead skin cells, creates an ideal environment for the proliferation of bacteria, which can contribute to inflammation and the development of acne lesions. This comedogenic process is directly related to the overproduction of sebum, the skin's natural oil, which is a hallmark of acne.

In contrast, the other listed conditions, such as eczema, psoriasis, and dermatitis, are associated with different symptoms and underlying causes, such as inflammation, dry skin, or immune responses, rather than excessive oiliness and clogged pores. Therefore, understanding that acne is specifically defined by its relationship to oiliness and pore blockage reinforces why it is the correct answer in this context.