Frequency of X-linked ichthyosis in coastal southern Italy: a study on a representative sample of a young male population.

BACKGROUND: No reports on the frequency of X-linked ichthyosis (XLI) in the Italian general population and few surveys on the frequency of XLI in large communities in the world are available.

OBJECTIVE: The aim of this study was the assessment of the frequency of XLI in a large representative sample of the Italian male population.

SUBJECTS AND METHODS: This study involved young men who enlisted as conscripts in the Italian Navy from January 1998 through February 2002, examined, prior to enlistment, at the Draft Council's Medical Unit of the Italian Navy in Taranto, Italy, to evaluate their psychophysical fitness. All the patients with an ichthyosiform condition were referred to the Department of Dermatology of the Navy Hospital, underwent a thorough dermatological examination and completed a questionnaire regarding their personal and familial history. Pertinent results of the other clinical investigations were recorded and the final diagnosis was formulated on the basis of all these data.

RESULTS: From January 1998 through February 2002, of 75,653 young men examined, 15 cases of XLI were diagnosed, with a frequency of 1:5,043 or 1.98 per 10,000 (95% confidence interval based on the Poisson distribution 1.01-2.90). Four out of 15 cases (26.6%) showed corneal opacities. No other significant associated pathological change was observed.

CONCLUSIONS: As this study is a survey involving a large male sample, homogeneous with reference to age, race and country of origin (southern Italy), the frequency of XLI could be estimated at about 1.98 per 10,000 males. These data are roughly in agreement with estimates from other European surveys.