Preferred treatments by types of acne vulgaris

• Comedonal (non-inflammatory) acne: local treatment with azelaic acid, salicylic acid, topical retinoids, benzoyl peroxide.
• Mild papulo-pustular (inflammatory) acne: benzoyl peroxide or topical retinoids, topical antibiotics (such as erythromycin).
• Moderate inflammatory acne: benzoyl peroxide or topical retinoids combined with oral antibiotics (tetracyclines). Isotretinoin is an option.
• Severe inflammatory acne, nodular acne, acne resistant to the above treatments: isotretinoin, or contraceptive pills with cyproterone for females with virilization or drospirenone.
• Most physicians state that topical retinoids are the preferred treatment for all forms of acne vulgaris

Wikipedia