title: A masquerade presenting with diplopia.
abstract: BACKGROUND
  Diplopia can often be a diagnostic challenge in the general practice setting. Differentials broadly include orbital pathology and neuromuscular aetiologies. Familiarity with the causes and subsequent investigations can help deliver efficient and effective patient care.
  
  
  OBJECTIVE
  This article presents a unique case to illustrate the diagnostic approach to diplopia and highlights a commonly encountered yet often overlooked condition as a differential to diplopia in general practice.
  
  
  CONCLUSIONS
  John Murtagh's manual identifies seven 'masquerades' as diagnoses that are commonly missed in general practice. The Murtagh model can be appropriately applied to diplopia in reminding practitioners of differentials that can easily slip from one's mind, yet can be diagnosed promptly with simple investigations. Atypical presentations of common disease processes should always be considered within the diagnostic framework for practitioners.
authors.affiliation: MBBS, Intern, The Alfred Hospital, Melbourne, VIC.
authors.forename: Xiao
authors.initials: X
authors.lastname: Chen
authors.forename: Awaldeep
authors.initials: A
authors.lastname: Singh
authors.forename: Satpal
authors.initials: S
authors.lastname: Singh
mesh_terms: D003937:Diagnosis, Differential; D004172:Diplopia / Q000209:etiology*; D005260:Female; D049970:Graves Ophthalmopathy / Q000150:complications* / Q000175:diagnosis / Q000188:drug therapy; D006801:Humans; D008875:Middle Aged; D009759:Nystagmus, Pathologic / Q000209:etiology; D013960:Thyroid Function Tests; D014057:Tomography, X-Ray Computed