What's the diagnosis?
December 10, 2024
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The case
New parents ask you about the rash on their 1-day-old infant’s face. They are anxious and wish to know if it will go away. The newborn is healthy, is breastfeeding nicely and all vital signs are normal. This rash was noted at birth.
Nevus simplex
This is nevus simplex, a benign vascular birthmark. Nevus simplex is due to a capillary malformation that occurs when the capillaries (small blood vessels that connect arteries to veins) are larger than normal. Because the capillaries are close to the surface of the skin, that area appears more pink or red in color.
The lesions of nevus simplex are flat and, being a birthmark, are present at birth. They are most frequently found on the head and neck - on the nape of the neck, glabella (space between the eyes), forehead and upper eyelids.
Nevus simplex affects infants of all races; it occurs in approximately 40% of Caucasian infants and less often in darker-skinned infants. It affects male and female infants equally.