What is acne?
Inflammatory acne also involves raised red bumps (papules), possibly with pus emerging at the top forming pustules. If the inflammation is deeper in the skin, there may be red and painful thickening (nodules), which progresses to cysts and abscesses. If scratched, crusts may form. Scarring may remain after nodules have healed. It is more like if there has been scratching or secondary infection.