Which symptom distinguishes Cushing syndrome from other diseases?

Cushing syndrome is characterized by an excess of cortisol in the body, often leading to distinct physiological changes. One of the hallmark symptoms of Cushing syndrome is the development of a condition known as 'moon facies,' which refers to a rounded face due to fat accumulation, as well as others symptoms such as central obesity, purple striae, and skin changes.

Onychomycosis, which is a fungal infection of the nails, is not typically a primary feature of Cushing syndrome. However, the correct answer relates to the unique symptoms associated with Cushing syndrome that differentiate it from other conditions, particularly the skin changes that can occur due to changes in cortisol levels.

Increased appetite, hair loss, and hyperactivity, while they may accompany various health conditions, do not serve as distinguishing features of Cushing syndrome. Increased appetite can be seen in multiple endocrine disorders, hair loss can result from numerous factors including stress and hormonal changes, and hyperactivity might be associated with conditions such as hyperthyroidism or other psychiatric issues.

The distinctive symptoms of Cushing syndrome, particularly related to skin changes and fat distribution, are essential in differentiating it from other diseases, making it crucial to identify these unique characteristics when considering a diagnosis.