Acne

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit built on four interacting processes: androgen-driven sebum production, abnormal follicular keratinisation that plugs the pore, proliferation of Cutibacterium acnes within it, and the inflammatory response — genetics loading the dice heavily (twin studies attribute most susceptibility to heredity). It affects around 85% of adolescents, persists or first appears in adulthood in a growing share — up to a quarter of women in their forties report it — and none of it is caused by dirt: overwashing and scrubbing worsen the barrier and the inflammation. The reframe matters clinically because the hygiene myth delays treatment, and delay is what converts an inflammatory disease into permanent scars.

Modern management is a ladder matched to severity and scarring risk. Mild comedonal disease: topical retinoids (adapalene now over-the-counter in several countries) as the foundation, with benzoyl peroxide added for inflammatory lesions. Moderate: fixed combinations — retinoid plus benzoyl peroxide plus, where needed, a topical antibiotic (never a topical or oral antibiotic alone: resistance stewardship is now core guideline doctrine, with courses time-limited and always paired with benzoyl peroxide); the first fixed triple-combination gel was approved in 2023, and clascoterone cream added an entirely new class — the first topical antiandrogen usable in both sexes. Moderate-to-severe in women: hormonal therapy (combined oral contraceptives, spironolactone) targets the androgen driver directly. Severe, scarring or refractory disease: isotretinoin — the single most effective acne drug and the only one that changes the disease's natural course.

Isotretinoin achieves clearance in the large majority of patients within a course, with durable remission in most and a relapse rate around a fifth to a third (higher when dosed low or stopped early). Its genuine, absolute hazard is teratogenicity — pregnancy prevention programmes are mandatory and non-negotiable. Its most publicised fears have fared differently under evidence: large meta-analyses find no population-level causal link with depression or suicide — acne itself raises both, and mood typically improves with clearance — though idiosyncratic reactions cannot be excluded and monitoring is standard; the inflammatory-bowel-disease association weakened to non-significance in successive analyses; and routine monthly laboratory testing has been rationalised (baseline and peak-dose lipids and liver tests suffice in healthy patients). The practical injustice is under-use: fear-driven avoidance leaves scarring disease undertreated — the harm profile of scars being permanent, and the drug's being mostly manageable and temporary.

Adult female acne — persistent or new-onset after 25, typically mandibular and premenstrual — responds to the standard ladder plus its hormonal rungs: combined contraceptives (several carry regulatory acne indications) and spironolactone, whose largest cohort and trial evidence has consolidated it as first-line systemic therapy for many women, safely and off-patent. Screening for polycystic ovary syndrome belongs in the workup when acne travels with irregular cycles or hirsutism. Two adjacent truths: acne cosmetica and pomade acne are real (comedogenic products matter, particularly with textured-hair care routines), and the diet question has matured — high-glycaemic-load diets and skim milk show reproducible modest associations, chocolate per se does not; dietary change is a legitimate adjunct, never a substitute.

Scarring — atrophic ice-pick, boxcar and rolling scars, keloids in predisposed skin — is acne's permanent tax, and its strongest predictor is duration of uncontrolled inflammation: hence the doctrine that scarring or scar-prone acne justifies escalation early, not after years of failed topicals. Post-inflammatory hyperpigmentation, the dominant concern in darker skin types, follows the same rule: it fades over months only if new lesions stop forming, and sun protection plus early effective treatment beat any fading cream. Established scars have real but partial remedies — resurfacing lasers, microneedling, subcision, fillers — all more expensive and less satisfying than the prevention that was available in tablet and cream form years earlier.

For teenagers and parents: start a topical retinoid early, expect six to twelve weeks before judging anything, wash twice daily gently and ignore the scrub aisle; escalate if control fails — normal adolescence does not require scarred skin. For adult women: the hormonal rungs (contraceptive choice, spironolactone) are often the answer conventional topicals were failing to be; ask about them, and about PCOS if cycles are irregular. For anyone offered long solo antibiotic courses: decline — modern guidelines cap duration and mandate benzoyl peroxide pairing. For severe or scarring disease: ask directly whether isotretinoin is appropriate, and judge it on the evidence rather than the folklore. And for everyone: the mental-health toll of acne is measured and real — treating the skin is treating that too.