Acne cause. Acne is not due to poor hygiene. It is generally accepted that acne develops due to build up of skin cells, oil (sebum) and bacteria in pores, which become infected. Cleansing skin too aggressively with harsh soaps and abrasives can irritate and inflame the skin making acne worse. Combination therapy includes gentle cleansing, topical or oral antibacterial therapy, moisturizing, sun protection, .