INTRODUCTION
Morphologically, acne vulgaris includes a mixture of primary and secondary lesions with a pattern unique to the individual patient. Acne lesions can be considered primary (papules, pustules, comedones) or secondary (erythema, dispigmentation, and scars). While acne scars have traditionally been categorized as sequelae (occurring after acne), it is important to recognize that scarring is a sequelae of an individual lesion and can begin early on in the course of the disease of acne and new scar formation can persist continuously until acne resolves. Post-acne scarring is known to be common in both genders (with some degree of scarring reported in up to 95% of acne cases);1-3 clinically relevant scars occur in approximately half of acne subjects. Although it is easy to assume that scars predominantly occur in patients with very severe acne, data have shown that scarring is a common phenomenon even with mild-to-moderate acne.2 There are relatively few published studies of the epidemiology and natural history of acne scarring. Prevention remains a primary strategy for acne scarring.4,5 Thus, it is important to determine which patients are at increased risk for scarring so that they can be identified with a goal of instituting effective acne therapy. Two studies reported increased likelihood of scarring with an increasing amount of time before effective acne therapy.1,2 Other risk factors for atrophic acne scarring have not been extensively studied, but are thought to include: more severe acne, genetic factors, extent or duration of inflammation, ineffective inflammatory response, onset of acne at young age, frequent relapses, truncal localization, and ethnicity.1,6-8 The Global Alliance to Improve Outcomes in Acne, a group of dermatologists with an interest in acne research, conducted a pilot study of acne scarring utilizing a questionnaire administered in dermatologists offices. The results were analyzed and the questionnaire was refined to improve clarity of questions and the improved questionnaire was used in this study. The study objective was to assess the frequency of acne scars among patients with active acne who consulted with dermatologists. Secondary objectives were to describe the clinical pro le of acne patients who had acne scars, quantify risk factors and different types of acne scars, and assess the burden of acne scars on quality of life.
METHODS
The study was conducted from May 2012 to March 2013. A representative sample of office-based dermatologists was randomly selected from the national membership directory of dermatologists. Physicians were contacted by phone to
