FAU Advanced Health Assessment Practice Test

A large, smooth-bordered bluish mark on an infant's buttock is likely which type of birthmark?

1. Cafe-au-lait spot

2. Salmon patch

3. Mongolian spot

4. Vascular nevus

The correct answer is: Mongolian spot

A large, smooth-bordered bluish mark on an infant's buttock is indicative of a Mongolian spot. These birthmarks are a type of congenital dermal melanocytosis, commonly seen in infants, particularly those with darker skin tones. Mongolian spots typically appear as flat, bluish-gray marks that can resemble bruising and are most commonly located on the lower back and buttocks. They are caused by the presence of melanocytes in the deeper layers of the skin and usually fade over time, often disappearing within the first few years of life. In contrast, a cafe-au-lait spot usually presents as a light tan or brown color and tends to be irregularly shaped, while a salmon patch, often referred to as a "stork bite" when located on the nape of the neck, appears as a flat, pink mark. A vascular nevus, also known as a hemangioma, typically presents as a raised or red spot and involves the proliferation of blood vessels. These characteristics help distinguish the Mongolian spot from other types of birthmarks, confirming its identification in this scenario.