The association between idiopathic scoliosis and the number of acquired melanocytic nevi

Background: Several syndromes in which melanocytic nevi and scoliosis mere present in the same patient have been described. No control study has been made to date to determine whether there is a relationship between these dis orders. Objective: We attempted to demonstrate the association between acquired mel anocytic nevi (AMN) and idiopathic scoliosis (IS). Methods: We studied 93 patients with IS, aged 10 to 18 years, from our hosp ital. Controls were randomly selected from 2 schools; Adam's forward bendin g test was used to exclude persons With clinical scoliosis, and the control group finally comprised 101 pupils. An observational, cross-sectional stud y was done. All AMN 2 mm or larger observed on the body were counted by one dermatologist. Other variables reported as risk factors in the number of n evi were also considered. Reliability of AMN counts was previously demonstr ated. Results: The median number of AMN was 18 (range, 10-42) in the IS group and 8 (range, 3-13) in controls (P < .001). The persons with scoliosis had mor e non-AMN dermatologic lesions than the controls (P < .05). Light phenotype correlated with many AMN. On multivariate analysis only scoliosis and age accounted independently for the number of AMN. Conclusion: IS is associated with many AMN. Multiple AMN may become a diagn ostic marker for IS, and these two malformations might constitute a syndrom ic association.