Pathergy phenomenon is when a small red bump or pustule occurs 1 to 2 days after a forearm is pricked with a sterile needle. This test is often associated with Behcet’s disease having a low sensitivity but high specificity for the disease, as a positive test supports a diagnosis of Behcet’s and is not definite. This past week’s NEJM had a case of a patient with newly diagnosed Behcet’s disease and a positive pathergy test. Click on the links below to read the article from NEJM and learn more from the Hopkins Vasculitis Center.
(image courtesy of The Johns Hopkins Vasculitis Center)