ROME — Polymyalgia rheumatica may be the presenting manifestation of silent giant cell arteritis, and therein lies a diagnostic dilemma: Which patients need a temporal artery biopsy?
Polymyalgia rheumatica (PMR) is the most common inflammatory rheumatologic disease among the elderly. It would be inappropriate to subject everyone who has symptoms consistent with PMR to temporal artery biopsy. Yet giant cell arteritis is a diagnosis that physicians cannot afford to miss because of the risk of irreversible blindness when the vasculitis isn't promptly recognized and treated with high-dose steroids.
One scenario warranting a temporal artery biopsy involves the patient with typical PMR symptoms—including bilateral shoulder pain with or without bilateral pelvic girdle pain, and morning stiffness lasting more than 45 minutes—plus headache, tinnitus, visual abnormalities, or other potential manifestations of intracranial ischemia, Dr. Miguel A. Gonzalez-Gay said.
Temporal artery biopsy is also a must in patients who don't show marked clinical improvement in response to 15-20 mg/day of oral prednisone within 7 days. This lack of response to low-dose steroids is a strong indicator that one of PMR's plethora of mimicking conditions is at work. Giant cell arteritis belongs at the top of the list of candidates because of its catastrophic consequences if untreated, noted Dr. Gonzalez-Gay of the rheumatology division of the Hospital Universitario Marques de Valdecilla, Santander, Spain.
Another situation warranting temporal artery biopsy involves a patient with typical PMR symptoms plus high fever or other severe constitutional symptoms. Dr. Gonzalez-Gay routinely gets a temporal artery biopsy in patients with PMR symptoms and an erythrocyte sedimentation rate in excess of 80 mm/hr. In studies he has conducted, that's roughly 9% of all patients with typical PMR symptoms.
Among the other main conditions that may present initially as PMR are rheumatoid arthritis, systemic lupus erythematosus, ankylosing spondylitis, fibromyalgia, amyloidosis, hypothyroidism, hematologic malignancies, bacterial endocarditis and other infections, and solid cancers, particularly metastases to musculoskeletal sites.
Dr. Gonzalez-Gay said features that should alert physicians to the possibility of a diagnosis other than PMR fall into two broad categories: atypical symptoms, or lack of a marked therapeutic response to prednisone at 15-20 mg/day within 7 days. In reply to an audience question, the rheumatologist said he utilizes 15 mg/day of prednisone except in the most obese patients.
Red flags in the clinical interview include little or no worsening of symptoms with movement, minimal morning stiffness, and diffuse aching. Findings on physical examination that suggest a diagnosis other than PMR include fever with or without a heart murmur, visceral enlargement, painless adenopathies, and synovitis involving the small joints of the hands and feet, the rheumatologist continued.
Laboratory findings that are discordant with PMR include a positive high-titer antinuclear antibody, hematuria, elevated muscle or liver enzymes, severe anemia, and hematologic cytopenias.
Disclosures: Dr. Gonzalez-Gay declared having no conflicts of interest regarding his presentation.
Temporal artery biopsy is a must for patients not responding to 15-20 mg/day of oral prednisone within 7 days.
Source DR. GONZALES-GAY