Background: Facial acanthosis nigricans (FAN), defined as brown to black macular pigmentation with ill-defined margins and velvety appearance seen over a zygomatic region or anywhere on the face. Recently increased prevalence of FAN was observed in patients with metabolic syndrome (MS) and obesity. Aim: To determine the association of obesity, MS, and insulin resistance (IR) with FAN. Materials and Methods: An observational study including all 70 patients above 18 years of age with features of FAN. For each patient, parameters like waist circumference, waist–hip ratio, body mass index, blood pressure, fasting blood sugar, fasting lipid profile, fasting serum insulin, and HOMA2-IR were calculated along with dermoscopy. Data were collected, and analysis was done by using Fischer’s exact test. Results: Among 70 patients, the mean age of patients was 44.7 in males and 44.47 in females. The most common pattern of FAN was patchy type, which was more commonly seen in the temporal region apart from the classical zygomatic region. Dyslipidemia was seen in 58.5% of patients, and dysglycemia was seen in 54.3% of patients, and 31.5% of patients had IR. Based on Sharqie’s severity grading, the majority (45.7%) had grade 3 severity of FAN. Limitations: Histopathology was not done in our study and we had included patients irrespective of their diabetic status. Conclusion: FAN is a newer entity and is frequently misdiagnosed as a type of facial melanosis. There was no statistically significant association between the severity of FAN grading and the presence of factors like IR, MS, abdominal obesity, hypertriglyceridemia, dysglycemia, and hypertension in our study.
Vishwanath et al. (Thu,) studied this question.