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

BACKGROUND

Several syndromes in which melanocytic nevi and scoliosis were 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 disorders.

OBJECTIVE

We attempted to demonstrate the association between acquired melanocytic nevi (AMN) and idiopathic scoliosis (IS).

METHODS

We studied 93 patients with IS, aged 10 to 18 years, from our hospital. Controls were randomly selected from 2 schools; Adam's forward bending test was used to exclude persons with clinical scoliosis, and the control group finally comprised 101 pupils. An observational, cross-sectional study 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 nevi were also considered. Reliability of AMN counts was previously demonstrated.

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 more 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 diagnostic marker for IS, and these two malformations might constitute a syndromic association.