What distinguishes inflammatory acne from non-inflammatory acne?

Inflammatory acne is characterized by the presence of redness and swelling, which occurs as a direct response to infection or irritation in the skin. This inflammation is typically caused by the buildup of bacteria, sebum, and dead skin cells within hair follicles, leading to the formation of pustules or cysts. The redness and swelling are significant indicators of inflammation, distinguishing it from non-inflammatory acne, which does not exhibit these symptoms.

In contrast, non-inflammatory acne primarily manifests as open (blackheads) or closed comedones (whiteheads) and generally does not produce visible redness or swelling. This distinction is critical for accurate diagnosis and treatment strategies in acne management.

The other options do not accurately describe the characteristics of inflammatory and non-inflammatory acne. Non-inflammatory acne isn't limited to adults; it can occur in individuals of various ages. Additionally, inflammatory acne can indeed include comedones, especially in its early stages, as these may develop before inflammation becomes apparent. Lastly, while pain can be associated with inflammatory acne, non-inflammatory acne does not typically involve severe pain as a defining characteristic.