title: Orbital myositis posing as cluster headache.
abstract: OBJECTIVE
  To describe the case of a patient with recurrent orbital myositis who was thought to have cluster headaches for 6 years.
  
  
  METHODS
  Case report in an outpatient neuro-ophthalmology clinic.
  
  
  METHODS
  A 24-year-old man developed unilateral supraorbital pain, lacrimation, conjunctival hyperemia, nasal congestion, proptosis, and painful eye movements. The pain intensity varied over the course of each day and disappeared after 1 month. He had multiple attacks responsive to prednisone that were separated by months over the ensuing 6 years. Neuroimaging revealed an enlarged extraocular muscle.
  
  
  CONCLUSIONS
  Overlap in symptoms between recurrent orbital myositis and cluster headache delayed the diagnosis in this patient. Orbital myositis should be considered in patients with atypical cluster headache characterized by proptosis, painful eye movements, and pain that does not completely resolve after 3 hours.
authors.affiliation: Massachusetts Eye and Ear Infirmary, Department of Neuro-ophthalmology, 243 Charles St, Boston, MA 02114, USA. michael_lee@meei.harvard.edu
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lee
authors.forename: Simmons
authors.initials: S
authors.lastname: Lessell
mesh_terms: D000328:Adult; D003027:Cluster Headache / Q000209:etiology*; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D006801:Humans; D008297:Male; D009220:Myositis / Q000150:complications* / Q000175:diagnosis*; D009916:Orbital Diseases / Q000150:complications* / Q000175:diagnosis*; D012008:Recurrence