[Acute, hyperintense, and febrile cervicalgia. Crowned dens syndrome, a monofocal microcrystalline arthritis sometimes doubly misleading]. / Cervicalgies aiguës, hyperintenses et fébriles. Syndrome de la dent couronnée, une arthrite microcristalline monofocale parfois doublement trompeuse.

Microcrystalline arthritis sometimes have atypical localizations and presentations. The crowned dens syndrome, due to hydroxyapatite or calcium pyrophosphate deposits in peri-odontoid ligaments of the atlas, can provoke acute or chronic cervicalgia or misleading presentations such as meningitidis or fever of unknown origin. We present a particularly severe new case requesting urgent surgery, and a literature review to alert clinicians and prevent misdiagnosing this syndrome. Indeed, calcifications may be very discrete or just incidental and prevent a complete diagnostic approach.