1. Pathogenesis of Acne Follicular disease, comedo formation
Produced by the impaction and distension of the follicles with a
keratinous plug in the
lower infudibulum

3. Hyperproliferation and abnormal differentiation of keratinocytes
increased sebum secretion

4. Lower portion of follicle is dilated by retianed/entrapped sebum and keratinous materials

5. Disruption of follicular epithelium permits discharge of follicular contents into the dermis
Bacteria, keratin and sebum leads to release of proinflammatory mediators and accumulation of T helper cells, neutrophils and giant cells
Formation of inflammatory papules, pustules

6. Marked inflammation causes nodulocystic lesions

7. Provocative Factors Comedogenic, greasy, occlusive products
Ex. Pomade or gel used on the hair
Mechanical and frictional forces
Ex. Tight strap on a sports helmet
Repeated laser hair removal
Genetic factors
Hyperandrogenic states (PCOS), menstruation
Prolonged use of topical or oral steroids
Other skin irritants or chemical/industrial compounds
Make up, overexuberant washing

8. Histopathology Comedones Pustular Nodular
Thinned epithelium and a dilated follicular canal filled withlamellar lipid-impregnated keratinous materials
Pustular
Folliculocentric abscess surrounded by dense inflammatory exudate of lymphocytes and PMNs
Nodular
Indolent, contain plasma cells, foreign body giant cells, proliferation of fibroblast