Acne Vulgaris
In acne, there's blockage and chronic inflammation, +/- localised infection, in a pilosebaceous unit. A pilosebaceous unit contains a hair follicles and sebaceous gland (produce natural skin oils and waxy substance called sebum).
With acne, there's an increased production of sebum, which traps keratin (dead skin cells) and blocks the pilosebaceous unit. This leads to swelling and inflammation of the unit = Comedone.
This process is exacerbated during puberty as androgens cause hyperplasia of sebaceous glands → increased sebum production and blockage of the pilosebaceous units. This can therefore be improved with the use of anti-androgenic medication.
Management
1st line
Topical retinoid +/- benzoyl peroxide
Topical tretinoin + Abx
2nd line
Same as mild-moderate
Topical azelaic acid + Abx
COCP can be used instead of Abx in women
3rd line
Oral retinoid
N.B. Vitamin A acts as an antioxidant, protecting cells from damage due to free radicals. It also reduces sebum production and has anti-keratinisation properties.
Isotretanoin
This works to reduce inflammation, sebum production, and bacterial growth. However, it's very important to note that it's strongly teratogenic.
Side effects - Dry skin and lips, Photosensitivity of skin, Depression, Anxiety, SJS, TEN