to the editor: We would like to thank Drs. Fuloria and Kreiter for their review of the newborn examination in American Family Physician.1 The article was thorough and provided a problem-based approach to the newborn examination. However, we have concerns regarding the last statement of the article: “Dimples should never be probed and should be evaluated with magnetic resonance imaging before neurosurgical intervention.”1 This recommendation could be misinterpreted as stating that all sacral dimples require magnetic resonance imaging (MRI) and neurosurgical consultation.
In the reference cited in this sentence, Drolet states: “Most infants with sacral dimples that fall within the gluteal crease are healthy.”2 Drolet suggests that only high-risk dimples should undergo evaluation with radiologic imaging. “High-risk” dimples are defined as those that are (1) deep; (2) larger than 0.5 cm; (3) located within the superior portion of the gluteal crease or above (greater than 2.5 cm from the anal verge); or (4) associated with other cutaneous markers.2
Results of a study by Kriss and Desai3 showed that the incidence of cutaneous stigmas in a healthy neonate population was 4.8 percent. This study3 also evaluated 207 neonates with cutaneous stigmas and found that none of the infants with a simple midline dimple (meeting none of the three criteria listed above) had spinal dysraphism. Eight of the 20 (40 percent) atypical dimples (one of the criteria was met) were positive for sacral dysraphism.3
The data in this prospective study reveal that simple midline dimples are the most common dorsal cutaneous stigmata in neonates and pose an extremely low risk for sacral dysraphism. When none of the criteria are met, the negative predictive value for a simple dimple in this study was 100 percent. The cost of screening these dimples or clefts with MRI and neurosurgical consultation would be excessive and unnecessary.