Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder affecting adolescents and women of childbearing age. It is also considered one of the most common causes of infertility (1).It affects 4% to 21% of the female population when Rotterdam 2003 criteria are applied, with perhaps an increase in the last decade (2,3). The pathogenesis of PCOS remains poorly understood, with complex interactions between multiple factors, both genetic such as insulin resistance and hyperandrogenism and environmental, including prenatal androgen exposure and postnatal obesity (4).

Multiple comorbidities are associated with PCOS including decreased fertility, type 2 diabetes mellitus (5), coronary heart disease (6) and psychiatric disorders (7). More than one guideline exists to diagnose PCOS in adolescents, which also makes timely recognition difficult. According to Rotterdam 2003 Criteria, 2 out of 3 criteria should be present to diagnose PCOS 1) Oligo- or anovulation 2) Clinical and/or biochemical signs of hyperandrogenism 3) Polycystic ovaries and exclusion of other etiologies (congenital adrenal hyperplasia, androgen-secretion tumors, Cushing's syndrome etc.) (8). Another approach to diagnose PCOS in adolescents requires the presence of irregular menses or oligomenorrhea and evidence of hyperandrogenism, while polycystic ovarian morphology (PCOM) is not always included as a diagnostic element of PCOS (9). Hyperandrogenism can clinically manifest as hirsutism, acne, voice change and male-pattern baldness. It is found that 97% of PCOS patients have at least one dermatological skin condition especially acne, hirsutism and acanthosis nigricans (AN) (10).

Hirsutism is defined as excessive growth of terminal hairs on the face and/or body in a male-type pattern in women. The modified Ferriman-Gallwey (mFG) visual scoring method (11) scores hair growth in nine androgen-sensitive areas: upper lip, chin, chest, upper and lower back, upper and lower abdomen, thighs, and upper arms. This approach scales each area from 0 to 4 with a total score from 0 to 36. Hirsutism is clinically defined as 6 or more (12), 7 or more (13), and 8 or more (14) according to the population studied (15).

Although the accurate diagnosis of PCOS is often elusive, the differences in manifestation of hyperandrogenism such as hirsutism for similar androgen levels between ethnicities and races make it even more challenging. In a study of 288 women complaining of unwanted hair growth without hirsutism on physical examination (i.e., an mFG score of 5 or less), 50% of them were diagnosed with PCOS on further evaluation (16). The relationship between ethnicity and hirsutism is not fully understood. In a previously published study, it was found that the highest total mFG score was observed in Hispanic, Middle Eastern, African American and South Asian patients (17). It is also observed that Hispanics population exhibits a more severe phenotype of PCOS, both in terms of hyperandrogenism manifestations and metabolism dysregulation when compared to non-Hispanic White or Black populations (18). Hirsute women have increased activity of 5α-reductase [the enzyme that converts testosterone to a more potent metabolite dihydrotestosterone (DHT)] in their hair follicles (19), converting vellus hair to terminal hair in androgen-sensitive areas (20). An increase in 5α-reductase activity is found in girls at risk for development of PCOS in their early childhood as a result of increasing target tissue production of DHT (21).

In this study, we aim to define the variation in the total mFG score in adolescents across ethnicities and races, accounting for key factors such as body mass index (BMI), age and androgen concentrations.