A healthy 2-week-old term infant born to parents of South Asian origin has well-demarcated slate-grey to blue-black macules over the sacrum and buttocks, each 3 to 6 cm across. The overlying skin texture is normal and the lesions do not change with pressure. What is the correct counseling point?

• A They require biopsy to exclude melanoma
• B They usually fade significantly by school age ✓
• C They indicate underlying spinal dysraphism requiring MRI
• D They represent bruising from birth trauma and should be documented as suspected injury

Explanation

Congenital dermal melanocytosis (Mongolian spots) are benign collections of melanocytes arrested in the dermis, seen in up to 90 percent of Asian and African neonates. They are flat, non-progressive, and typically fade considerably during early childhood, so reassurance is appropriate. They can be mistaken for bruises and misreported as inflicted injury, so documentation matters, but their color, location, and presence from birth distinguish them from trauma. Sacral dimple or hairy tuft, not these flat macules, would prompt imaging.

Reference: Hurwitz Clinical Pediatric Dermatology, 5th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.