Temporal Arteritis Caused by Tertiary Syphilis.

A 77-year-old man arrived at our hospital with bilateral shoulder pain persisting for several months and headache for 1 month. Giant cell arteritis with polymyalgia rheumatica was suspected. However, considering his medical history of testing positive for syphilis, we submitted a sample for a syphilis serology test, which yielded positive results. The Treponema pallidum hemagglutination assay of cerebrospinal fluid was positive, and a temporal artery biopsy revealed vasculitis, confirming the diagnosis of tertiary syphilis. He was successfully treated for two weeks with penicillin G infusions. Symptoms reminiscent of giant cell arteritis and polymyalgia rheumatica may reveal syphilis, which is called the "great imitator."