What Makes Acne a Chronic Inflammatory Disease
Acne is a long-lasting skin problem that affects hair follicles and oil glands, turning into ongoing inflammation because of a mix of blocked pores, extra oil, bacteria, and immune reactions. It starts small but can lead to red bumps, pus-filled spots, and deep scars if not managed.
The trouble begins inside the pilosebaceous unit, which is the hair follicle and its attached oil gland. First, skin cells grow too fast and stick together in a process called hyperkeratinization. This clogs the pore opening, forming tiny plugs known as microcomedones. These blockages trap oil and debris, setting the stage for trouble.[1][5]
Next, oil glands, or sebaceous glands, pump out too much sebum, the oily stuff that keeps skin soft. Hormones like androgens, which rise during puberty or due to stress, push these glands into overdrive. The extra oil, mixed with altered fats, creates a perfect moist, airless spot for bacteria to grow. Sebum levels often match how bad the acne gets.[1][3]
Bacteria called Cutibacterium acnes, once known as Propionibacterium acnes, move in and make it worse. They release enzymes that break down oils into irritating free fatty acids, damage the skin barrier, and help form biofilms. These sticky bacterial shields protect them from the body’s defenses and treatments.[1][3][5]
This buildup triggers the immune system. The body spots the bacteria and sends in white blood cells like macrophages, lymphocytes, and neutrophils. They release chemicals that cause swelling, oxidative stress, and damage to the follicle wall. Sometimes the wall bursts, spilling contents into deeper skin layers. That leads to inflamed papules, pustules, nodules, and cysts.[1][5]
Inflammation does not stop there. It feeds back into the cycle, changing oil production to favor more bacteria and ramping up skin cell clogs. Stress adds neurogenic inflammation through nerves, lowering the threshold for immune attacks. Genetics, diet like high-sugar foods or dairy, and hormones keep the process going, making acne chronic instead of a quick fix.[1][2][5]
Other factors pile on. High insulin from sugary diets boosts oil and hormones. Conditions like PCOS raise androgens, worsening jawline breakouts in adults. Even skincare products or medications can irritate pores and spark more inflammation.[2][4][6]
Because multiple steps interconnect, acne persists over months or years, forming lesions in waves. Early spots take weeks to show, while deep cysts brew for months underground.[5]
Sources
https://pmc.ncbi.nlm.nih.gov/articles/PMC12735603/
https://www.westchestercosmeticdermatology.com/blog/adult-acne-why-it-happens-and-how-to-treat-it/
https://www.britannica.com/science/acne
https://www.fivensondermatology.com/acne
https://www.doctorrogers.com/blogs/blog/acne-pimples-101-why-we-break-out-what-s-actually-going-on-and-how-to-handle-it-like-a-dermatologist
https://www.tuftsmedicine.org/about-us/news/acne-over-30
https://www.ortho-dermatologics.com/conditions/featured-conditions/acne-vulgaris/
