[Acanthosis nigricans in children and Crouzon syndrome]

Crouzon syndrome with acanthosis nigricans is a rare form of Crouzon syndrome in which craniosynostosis and facial dysmorphism are associated with acanthosis nigricans.

Cutaneous examination of a 9-year-old child presenting bicoronal craniosynostosis revealed acanthosis nigricans of the cervical, axillar, inguinal and popliteal regions which appeared at the age of two. He had a dysmorphic face including a large forehead, hypertelorism, mid-face hypoplasia, prognathism and low-set ears. These clinical anomalies suggested a case of Crouzon syndrome with acanthosis nigricans, which was later confirmed by the finding of a mutation in the FGFR3 gene.

Acanthosis nigricans in children is often a cutaneous marker of insulin resistance. However, it may also form part of diverse diseases, notably those of genetic origin. The association of craniosynostosis and acanthosis nigricans allows incrimination of the FGFR3 gene from the outset and diagnosis of Crouzon syndrome with acanthosis nigricans. In the present case, dermatological examination allowed an aetiology of craniosynostosis to be determined.