Retropharyngeal tendinitis: Hydroxyapatite deposition driven headache and nuchal rigidity resolves with prednisone

We present a case of a 42-year-old woman who presented with sudden onset severe headache, neck pain, and nuchal rigidity associated with dysphagia. The initial differential in this patient included meningitis or retropharyngeal abscess, and an extracranial neck CT showed an ill-defined hypo-attenuated lesion within the retropharyngeal space. However, the neck pain and dysphagia were unresponsive to empirical antibiotic treatment and pain management. Further CT with contrast identified acute calcific tendonitis of the longus colli tendon, also known as retropharyngeal tendonitis (RCT). Although RCT is already known as a rare, self-limiting inflammatory condition, we present a new case of RCT, with the uncommon features of headache and nuchal rigidity in an aseptic patient, while providing a diagnostic flow chart to guide the clinical work-up of similar presentations to also include RCT.