Rosh Emergency Medicine Practice Test

What is most likely the underlying cause of velvety, hyperpigmented plaques on a young boy's neck?

1. Cortisol deficiency

2. Hyperinsulinemia

3. Mechanical friction and irritation

4. Proliferation of melanocytes

The correct answer is: Hyperinsulinemia

The presence of velvety, hyperpigmented plaques, particularly in areas such as the neck, suggests the condition known as acanthosis nigricans. This skin alteration is commonly associated with insulin resistance and hyperinsulinemia. In young individuals, particularly children and adolescents, this can often be a precursor or indicator of metabolic conditions such as obesity or type 2 diabetes. Hyperinsulinemia is an increase in insulin levels in the blood, often a response to insulin resistance where the body requires more insulin to maintain normal blood glucose levels. This persistent state leads to physiological changes in the skin, including the growth and thickening of the epidermis, which manifests as the characteristic velvety appearance of the plaques. While other factors could contribute to skin changes, such as hormonal imbalances (like cortisol deficiency) or mechanical irritation, the link between insulin resistance and the distinct appearance of acanthosis nigricans makes hyperinsulinemia the most relevant underlying cause in this context.