Introduction: Acne occurring in adults over the age of 25 years is known as acne tarda or adult acne. Three types of adult acne are recognized: persistent, late-onset, and recurrent acne. Most studies do not compare the characteristics between the three variants. In addition, little is known about adult acne in males. This study describes the epidemiological factors of adult acne and investigates certain triggering factors by sex and different types of adult acne. Methods: A multicenter, prospective, descriptive study was conducted. Patients with adult acne and an acne-free control group were compared regarding medical history, family history, smoking and drinking habits, and dietary factors. In addition, triggering and prognostic factors were investigated by sex and three different types of acne: persistent, late-onset, and recurrent acne. Results: The participants included 944 (88.56%) female and 122 (11.44%) male patients with adult acne, and 709 (73.85%) female and 251 (26.15%) male control patients. The consumption of crackers, chocolate, and pasta was significantly more common in the acne group than in the control group (p = 0.017, 0.002, and 0.040, respectively). Male patients with adult acne had a significantly longer disease duration than female patients with adult acne (p = 0.024). The most common type of acne was recurrent acne, followed by persistent and late-onset acne. Among patients with persistent acne, 14.5% had polycystic ovary syndrome (PCOS), whereas 12.2% of patients with recurrent acne and 11.1% of patients with late-onset acne had PCOS. Severe acne was more common in the persistent acne type (28.13%). The cheek (59.90%) was the most common involvement area, and stress (55.23%) was the most common triggering factor regardless of sex. Conclusions: Although adult female and male patents with adult acne share similar triggering factors, the involvement areas can differ, which may indicate the additional hormonal etiology of female adult acne. Further epidemiological studies on adult acne in both sexes may illuminate the pathogenesis of the disease, thus making possible the development of new treatment strategies.