Which skin condition is characterized by redness, swelling, and pus-filled lesions?

Acne vulgaris is identified by its hallmark symptoms of redness, swelling, and the presence of pus-filled lesions, often referred to as pustules. This skin condition arises primarily due to clogged hair follicles and excess oil production, leading to the inflammation of the skin. The bacteria Propionibacterium acnes can also play a significant role in the development of these lesions, contributing to the redness and swelling.

In contrast, the other conditions listed have different characteristics. Psoriasis typically presents with thick, scaly patches rather than pus-filled lesions. Eczema is more associated with dry, itchy areas of skin and may result in fluid-filled blisters, but it does not generally form pus-filled lesions. Dermatitis, while it can involve redness and swelling, is a broader term including various types of skin inflammation and does not specifically highlight the pustular aspect that defines acne vulgaris. Thus, acne vulgaris is correctly identified for its distinct presentation involving pustules and associated inflammatory symptoms.