How Pimples Form: The Four Key Factors

Pathogenesis of Acne

1. Excess Sebum – Androgens stimulate sebaceous glands; oil overproduction.
2. Follicular Hyperkeratinization – Dead skin cells don't shed properly, clogging the pore (microcomedo).
3. Cutibacterium acnes Proliferation – Anaerobic bacterium thrives in sebum-rich, low-oxygen environment.
4. Inflammation – Bacterial products trigger immune response; neutrophils accumulate → pustule; deeper inflammation → nodule/cyst.

Clinical Correlation

• Whiteheads/blackheads = non-inflammatory (steps 1–2).
• Papules/pustules = inflammatory (steps 3–4).
• Nodules/cysts = deep inflammation, scarring risk.

Treatment targets one or more steps: retinoids (keratinization), benzoyl peroxide/antibiotics (bacteria), anti-inflammatories, hormonal therapy (sebum).