Chewing gum to help diagnose giant cell arteritis
This week we published work assessing the “chewing gum test” to help diagnose giant cell arteritis (CGT). This test involves a patient chewing gum for 5 minutes as part of the clinical assessment for GCA.
Jaw claudication, whereby patients describe pain in the jaw on prolonged chewing, is a typical symptom of GCA. It is caused from reduced blood flow to the muscles of mastication (chewing) due to vasculitis of the feeding arteries.
The problem for clinicians is that jaw pain can be due to many other causes including temporomandibular (TMJ) joint arthritis, TMJ dysfunction and bruxism (teeth grinding).
Our study showed that if the onset of jaw pain when chewing gum is delayed (especially after 2 minutes), the chance of GCA is much higher. This makes sense. TMJ dysfunction and bruxism will typically result in discomfort immediately on jaw movement.
I used the CGT last week in my clinic to tease out the cause of jaw pain in a patient who may have had GCA. The onset of pain was delayed at 1.5 minutes which made me more suspicious of the diagnosis. The diagnosis of GCA was confirmed on ultrasound and temporal artery biopsy.