Giant Cell Arteritis (Temporal Arteritis) Differential Diagnoses

Updated: Jul 07, 2022
  • Author: Mythili Seetharaman, MD; Chief Editor: Herbert S Diamond, MD  more...
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Diagnostic Considerations

Many of the clinical manifestations of giant cell arteritis (GCA) are nonspecific, and consequently the differential diagnosis is long. GCA can cause blindness, and this dreaded complication can often be prevented with prompt diagnosis and institution of therapy. Failure to do so represents a medicolegal pitfall in addition to suboptimal medical practice. Treatment is long and often complicated, however, so overdiagnosis also has hazards.

Polymyalgia rheumatica

Polymyalgia rheumatica (PMR) is a clinical syndrome characterized by aching in the proximal portions of the extremities and torso. Diagnostic criteria include aching and morning stiffness lasting half an hour or more in 2-3 commonly affected areas (eg, neck, shoulder girdle, hip girdle) for at least 1 month in a person aged 50 years or older. Aching and stiffness are also worse with exertion, and may be severe and incapacitating.

In PMR, muscles may be tender, disuse may lead to atrophy, and contractures may develop. Muscle strength is usually normal but is often difficult to evaluate because of pain.

In typical cases of PMR without vasculitic involvement of the peripheral nervous system, electromyographic (EMG) results are normal. Mild EMG abnormalities in an elderly patient that suggest a mild peripheral neuropathy are generally unrelated to PMR or vasculitis. Erythrocyte sedimentation rate (ESR) elevation (40-50 mm/h via Westergren method) is typically found, with a rapid response to small doses of corticosteroids (prednisone 10 mg/d).

PMR is a diagnosis of exclusion. The presence of other specific disease entities, such as GCA, rheumatoid arthritis, polymyositis, chronic infection, or malignant neoplasm, must be ruled out.

PMR often coexists with GCA. In some series, 10-15% of patients with pure PMR had associated GCA based on temporal artery biopsy findings. Conversely, 50-70% of patients with GCA had associated PMR. No difference is evident in the degree of ESR elevation, the presence of minor visual symptoms, sex, age, or the duration of symptoms between patients with PMR and GCA and those with PMR only; furthermore, approximately 10% of patients with PMR and localized temporal artery signs have negative biopsy findings.

Other disorders

Granulomatosis with polyangiitis (formerly known as Wegener granulomatosis) and polyarteritis nodosa may occasionally affect the temporal artery and cause clinical findings similar to GCA. Other vasculitides, such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and Takayasu arteritis, may have similar signs and symptoms.

GCA and Takayasu arteritis have overlapping symptoms in varying frequencies, and when GCA involves larger vessels, the lesions are indistinguishable from those observed in Takayasu arteritis. Thus, these two disorders may represent a spectrum of presentation rather than distinct disease entities. [84]

Amyloidosis rarely affects temporal arteries. It may cause jaw or arm claudication. [85]

Other problems to be considered include the following:

  • Dental conditions
  • Sinus disease
  • Carotid disease and stroke
  • Dissection
  • Connective tissue disease
  • Systemic infections
  • Neoplasms
  • Arteriosclerotic vascular disease
  • Arteriovenous fistulas
  • Other forms of vasculitis

Differential Diagnoses