Acne vulgaris is a chronic inflammatory condition of the pilosebaceous unit, typically starting at puberty. The prevalence rate of 85% has been estimated among persons aged 12-24 years. Acne formation is influenced by four major factors: androgen-induced increased sebum production, altered keratinization within the follicle, increased colonization of the pilosebaceous duct Cutibacterium acnes, and release of inflammatory mediators. Clinical features include non-inflammatory lesions (open and closed comedones), inflammatory lesions (papules, pustules, nodules), and various degrees of scarring. Acne may present as a mild (comedonal acne), moderate (mild to moderate papulopustular acne), or severe disease (severe papulopustular/moderate nodular acne, severe nodular/conglobate acne, and acne fulminans). All severe acne vulgaris require systemic treatment with oral isotretinoin as the firstline treatment. Isotretinoin decreases the proliferation of sebocytes and sebum production, reduces the colonization of Cutibacterium acnes secondarily, normalizes the keratinization process within the follicle, and inhibits inflammation. Oral hormonal antiandrogens and oral antibiotics may be used as an alternative therapy. Acne fulminans is a rare and severe form of inflammatory acne, presenting with an abrupt onset of painful, hemorrhagic pustules and ulceration, usually accompanied by systemic symptoms (fever, polyarthritis, and laboratory abnormalities). Systemic corticosteroids are recommended as the initial treatment due to their anti-inflammatory effect. After 2-4 weeks, isotretinoin can be added with the corticosteroid/isotretinoin overlap for at least four weeks.