title: Diagnostic Algorithm for Patients With Suspected Giant Cell Arteritis.
abstract: BACKGROUND
  To identify clinical and laboratory factors contributing to the diagnosis of giant cell arteritis (GCA) and develop a diagnostic algorithm for the evaluation of GCA.
  
  
  METHODS
  Retrospective review of 213 consecutive cases of temporal artery biopsy (TAB) seen at a single academic center over a 10-year period (2000-2009). Pathologic specimens were re-reviewed and agreement between the original and second readings was assessed. A composite clinical suspicion score was created by adding 1 point for each of the following criteria: anterior extracranial circulation ischemia, new onset headache, abnormal laboratory results (erythrocyte sedimentation rate, C-reactive protein (CRP), or platelet count), jaw claudication, abnormal or tender superficial temporal artery, constitutional symptoms, and polymyalgia rheumatica; one point was subtracted if a comorbid condition could explain a criterion.
  
  
  RESULTS
  Of the 204 TABs analyzed, pathologic findings were confirmatory in 49 (24.0%) and suggestive in 12 (5.9%). TAB-positive patients were more likely to be older (age 75.2 ± 7.8 vs 69.7 ± 11.0 years, P = 0.0002), complain of jaw claudication (relative-risk = 3.26, P = 0.0014), and have thrombocytosis (relative-risk = 3.3, P = 0.0072) and elevated CRP (relative-risk = 1.8, P = 0.037). None of the patients with a clinical score less than 2 had a positive TAB. Diabetes mellitus and kidney disease were often the explanation for the symptoms and abnormal clinical finding(s) that led to a negative TAB.
  
  
  CONCLUSIONS
  We propose a clinical algorithm that is highly predictive for a positive TAB and can be valuable in the evaluation process of suspected cases of GCA.
authors: Departments of Ophthalmology (MAE-D, LC, ADP, TJC, SSS, MTB), Pathology (ADP, TJC), Biostatistics and Bioinformatics (SSS), and Neurology (MTB), Duke Eye Center and Duke University Medical Center, Durham, North Carolina.
authors: Mays A
authors: MA
authors: El-Dairi
authors: Lan
authors: L
authors: Chang
authors: Alan D
authors: AD
authors: Proia
authors: Thomas J
authors: TJ
authors: Cummings
authors: Sandra S
authors: SS
authors: Stinnett
authors: M Tariq
authors: MT
authors: Bhatti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001799:Blood Sedimentation; D002097:C-Reactive Protein; D003937:Diagnosis, Differential; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D013700:Giant Cell Arteritis / Q000175:diagnosis*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D012372:ROC Curve
chemical_list: D002097:C-Reactive Protein