Malformation de la charnière cervico-occipitale et vitiligo

Vitiligo is a relatively common multifactorial polygenetic dermatosis (0.5%-2% of general population) characterized by segmental or nonsegmental cutaneous depigmentation. Chiari malformation is a congenital cervico-occipital junction disease characterized by a migration of a part of the cerebellum through the foramen magnum.The association between these two pathologies is exceptional and poses a cause-effect problem. We here report the case of a 45-year old woman with no particular previous history who reported bilateral cervico-brachial neuralgias associated with thermal algesic dissociated sensory disorders lasting for 2 months. Cutaneous examination showed hypopigmented macular lesion on the neck and the posterior portion of the right forearm resistant to topical treatment based on strong corticosteroids (A). Brain MRI objectified Chiari malformation type II (B red arrow) with syringomyelia cavity at C6 (B white arrow). The patient underwent osteo-dural decompression of the posterior fossa with good neurological improvement and repigmentation of patches after 6 months. A few cases have been reported in the literature that show this association. Arguments in favor are: localization of lesions in dermatomes in correspondence with the malformation and regression after surgery. Etiopathogenesis of vitiligo is not clear, then several theories have been proposed to explain its occurrence;autoimmune theory, epidermal adhesion theory, biochemical theory and neuronal theory.This last seems to us to be the most likely explanation of this association. According to this theory the occurrence of skin lesions is due to the secretion of substances inducing melanocyte destruction by suffering neurons.