Acne

Four factors are usually described together: increased sebum production, abnormal shedding of cells inside the follicle, the skin bacterium Cutibacterium acnes, and inflammation. Hormonal shifts, genetics, some medicines and occlusive products can influence it; evidence around diet is mixed and individual.

Over-the-counter care generally combines a gentle cleanser, a non-comedogenic moisturiser, daily sunscreen and one active such as salicylic acid, benzoyl peroxide, azelaic acid, niacinamide, or an adapalene-type retinoid where it is available without prescription. Introduce actives one at a time, expect weeks rather than days, and stop scrubbing — mechanical aggression worsens inflammation.

Nodular, cystic or scarring acne, acne that does not respond to consistent care, or acne that is causing significant distress is a medical matter: a dermatologist can offer prescription options. Retinoids are not used in pregnancy, and picking or squeezing increases the risk of marks and scars.