Insulin-resistant acanthosis nigricans, type A (IRAN, Type A) is a patch of velvety pigmented skin that arises in correlation with insulin-resistant diabetes mellitus. The clinical features include diabetes mellitus, acanthosis nigricans, and blackish, soft skin patches. Worldwide epidemiologic studies proposed that acanthosis nigricans is an effective marker for insulin resistance amongst obese subjects despite of the geographic location. Children of any ethnic group with a body mass index greater than the 98th percentile have a 62% prevalence of acanthosis nigricans, while the malignant acanthosis nigricans (benign form) has no tendency towards a specific ethnic group. IRAN, Type A affects both males and females equally. Lesions of benign acanthosis nigricans may occur at any age including at birth, though it is more common within adult population. Malignant acanthosis nigricans arises more frequently in elderly people; yet cases were described in children with Wilms tumor, gastric adenocarcinoma, and osteogenic sarcoma.
[See: Somalia > Bushnaq and Shaltout, 1989].
Bushnaq and Shaltout (1989) reported a 9 year old Somali girl with diabetes, who was found to suffer from numerous somatic anomalies and acanthosis nigricans upon physical examination. The patient underwent biochemical and hormonal examinations which demonstrated only glucose metabolism abnormality and upon treatment she was found to be insulin resistant, which made attaining normoglycemia unachievable.
Lestringant et al., (2000) studied the association of Acanthosis nigricans, hyperinsulinemia, and hormonal levels in 92 female subjects with Acanthosis nigricans from the United Arab Emirates (age range 16-65 years). Of these 92 females, 36 subjects were considered to have diabetes mellitus (DM) and 56 were euglycemic. The analysis showed that in cases of family history of DM, HDL-cholesterol (mmol/l) and uric acid (mmol/l) levels were higher. Overall, DM subjects had significantly higher values for hormone levels of TSH, FSH, LH, progesterone, testosterone, cortisol, prolactin, (growth hormone) GH, and ferritin. One year later, Bener et al. (2001) conducted a similar matched case-control study involving 184 female subjects (92 females with A. nigricans and 92 females without A. nigricans); (age range 16-65 years). BMI, family history of DM, fasting, glucose, HDL-cholesterol (mmol/l), triglycerides (mmol/l) and uric acid (mmol/l) levels were statistically significantly higher in obese women in acanthosis and non acanthosis groups. The results revealed that BMI, family history of DM, total cholesterol (mmol/l), triglycerides (mmol/l) and uric acid (mmol/l) levels were statistically significant higher in diabetic women in non-acanthosis. Furthermore, systolic blood pressure, total cholesterol (mmol/l), triglycerides (mmol/l) and uric acid (mmol/l) levels were statistically significantly higher in diabetic women in acanthosis groups. Overall, DM subjects had significantly higher values for hormone levels of TSH, FSH, LH, progesterone, testosterone, cortisol, prolactin, GH, and ferritin.