Existing scoring systems for facial acne focus on the lesions themselves, but clinical decisions are based on a general assessment of severity, including the time since onset, the site(s) of involvement, the patient's history, and the response to prior treatments. The aim of this study was to investigate the influence of some of these factors on the global assessment of acne severity. Involvement of the trunk, prior systemic treatment and a positive family history of acne increased the severity score. Inclusion of these factors could help to compose more homogeneous groups for clinical trials.