Importance: Understanding of the associations among cutaneous findings, systemic abnormalities, and fulfillment of the diagnostic criteria in women suspected of having polycystic ovary syndrome (PCOS) is incomplete.

Objective: To identify cutaneous and systemic features of PCOS that help distinguish women who do and do not meet the diagnostic criteria.

Design, setting, and participants: Retrospective cross-sectional study of a racially diverse referred sample of women seen at the University of California, San Francisco, Polycystic Ovary Syndrome Multidisciplinary Clinic over a 6-year period between May 18, 2006, and October 25, 2012. Participants were 401 women referred for suspected PCOS. In total, 68.8% (276 of 401) met the Rotterdam PCOS diagnostic criteria, while 12.0% (48 of 401) did not. Overall, 11.5% (46 of 401) had insufficient data to render a diagnosis, 1.7% (7 of 401) were excluded from the study, and 6.0% (24 of 401) refused to participate in the study.

Exposure: Comprehensive skin examination and transvaginal ultrasonography. All patients were tested for levels of total testosterone, free testosterone, dehydroepiandrosterone (DHEAS), androstenedione, luteinizing hormone, and follicle-stimulating hormone. Levels of serum cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides were obtained, in addition to 0-hour and 2-hour oral glucose tolerance test (OGTT) results, with measurement of glucose and insulin levels.

Main outcomes and measures: Findings from comprehensive skin examination, laboratory testing, and transvaginal ultrasonography.

Results: In total, 401 women with suspected PCOS were included in the study. The median patient age was 28 years. Compared with women who did not meet the diagnostic criteria for PCOS, women who met the criteria had higher rates of hirsutism (53.3% [144 of 270] vs 31.2% [15 of 48], P = .005) (with higher mean modified Ferriman-Gallwey scores of 8.6 vs 5.6, P = .001), acne (61.2% [164 of 268] vs 40.4% [19 of 47], P = .004), and acanthosis nigricans (AN) (36.9% [89 of 241] vs 20.0% [9 of 45], P = .03). Cutaneous distributions also varied. Women who met the PCOS criteria demonstrated more severe truncal hirsutism and higher rates of axillary AN. Women who met the PCOS criteria had elevated total testosterone levels (40.7% [105 of 258] vs 4.3% [2 of 47], P < .001). Among women with PCOS, the presence of hirsutism (43.9% [54 of 123] vs 30.9% [34 of 110], P = .04) or AN (53.3% [40 of 75] vs 27.0% [40 of 148], P < .001) was associated with higher rates of elevated free testosterone levels as well as several metabolic abnormalities, including insulin resistance, dyslipidemia, and increased body mass index. Although the prevalence of acne was increased among women with PCOS, there were minimal differences in acne types and distribution between the women meeting vs not meeting the PCOS criteria.

Conclusions and relevance: Hirsutism and AN are the most reliable cutaneous markers of PCOS and require a comprehensive skin examination to diagnose. When present, hirsutism and AN should raise clinical concern that warrants further diagnostic evaluation for metabolic comorbidities that may lead to long-term complications. Acne and androgenic alopecia are prevalent but unreliable markers of biochemical hyperandrogenism among this population.

• UL1 TR000004/TR/NCATS NIH HHS/United States