Acne & Breakouts

Acne is the most common skin condition worldwide and one of the most persistently mismanaged, largely because the visible lesion is the last step in a process that began weeks earlier. The pathogenesis has four interlocking components. Androgens increase sebum production at puberty. Abnormal keratinisation of the follicular lining creates a plug — the microcomedone, invisible and present long before any spot appears. Cutibacterium acnes proliferates in the resulting anaerobic, lipid-rich environment. And the immune response to that, mediated partly through toll-like receptor 2, produces the inflammatory papules and pustules people actually notice. That sequence explains the two most important treatment principles. First, treatment must target the microcomedone, which is why topical retinoids — the only agents that normalise follicular keratinisation — belong in almost every regimen regardless of acne type. Second, treatment has to be applied to the whole affected area rather than spot-treated, because you are preventing lesions that have not surfaced yet. Timelines matter for expectations. A microcomedone takes roughly eight weeks to become a visible lesion, so any regimen needs a minimum of twelve weeks before it can be judged. Purging in the first few weeks of retinoid use is the pre-existing pipeline surfacing faster, not the treatment failing. Diet has a real but secondary role. High-glycaemic-load diets and skim milk show consistent associations across observational studies and some trial support; chocolate and greasy food, the traditional culprits, do not.

• •Blackheads and whiteheads (comedones)
• •Inflamed red papules
• •Pustules with a visible white or yellow head
• •Deep, tender nodules under the skin
• •Oily skin, particularly across the T-zone
• •Post-inflammatory hyperpigmentation — dark marks after lesions heal
• •Atrophic or raised scarring
• •Distribution over face, chest, upper back and shoulders

• •Androgen-driven increase in sebum production
• •Abnormal follicular keratinisation forming microcomedones
• •Cutibacterium acnes proliferation
• •Inflammatory immune response within the follicle
• •Genetic predisposition — strongly familial
• •Polycystic ovary syndrome and other hyperandrogenic states
• •High glycaemic load diet
• •Skim milk and whey protein supplements
• •Comedogenic cosmetics and hair products
• •Mechanical friction from helmets, straps and masks
• •Medications including corticosteroids, lithium and anabolic steroids

The initiating event in acne is not bacterial and not dietary — it is hormonal and follicular. Rising androgens at puberty enlarge sebaceous glands and increase sebum output, while the follicular epithelium simultaneously becomes hyperkeratotic and fails to shed normally. The microcomedone that forms is the true lesion of acne; everything visible follows from it. C. acnes is best understood as an opportunist rather than a pathogen. It is present on everyone's skin, and it is specific strain populations and the host inflammatory response to them, rather than sheer bacterial load, that correlate with disease. This is why antibiotic monotherapy fails and breeds resistance, and why guidelines now insist antibiotics be paired with benzoyl peroxide and limited to three months. The dietary contribution operates through insulin and IGF-1. High glycaemic load raises insulin and free IGF-1, which increases androgen availability and directly stimulates sebocyte proliferation. Skim milk raises IGF-1 more than whole milk, which is the leading explanation for the consistent skim-milk association in cohort studies. Persistent adult acne, particularly along the jawline in women, should prompt consideration of PCOS — irregular periods, hirsutism and acne together warrant investigation.