What characterizes acne vulgaris?

Acne vulgaris is primarily characterized by increased sebum secretion. Sebum is an oily substance produced by sebaceous glands in the skin. During acne vulgaris, there is an overproduction of sebum, which can lead to clogged pores when it mixes with dead skin cells. This environment is conducive to the growth of specific bacteria, particularly Propionibacterium acnes, which can further exacerbate inflammation and lead to the formation of acne lesions, including pimples and cysts.

In contrast, the other options do not accurately relate to acne vulgaris. Increased muscle growth does not have a connection to the condition; acne is more related to skin and gland activity. Decreased skin sensitivity is not a characteristic of acne vulgaris, as the condition often causes irritation and inflammation, resulting in increased sensitivity. Finally, increased hair follicle strength is not relevant; instead, blocked follicles contribute to the manifestation of acne. Understanding the role of sebum helps clarify why its overproduction is a key factor in the development and persistence of acne vulgaris.