Syphilitic periostitis in a newly diagnosed HIV-positive man

A 36-year-old man presented for an HIV test, which answered positive. He gave a six-week history of headache and fever. His syphilis serology was also positive with a Venereal Disease Research Laboratory (VDRL) titre of 1:32, and positive Treponema pallidum particle agglutination (TPPA) assay and fluorescent treponemal antibody (FTA). When he attended for treatment of the syphilis, he had developed severe pain in both lower limbs. Plain radiographs were normal. An isotope bone scan showed multiple areas of increased uptake, consistent with syphilitic periostitis. Some of these lesions were asymptomatic. He was treated with benzathine penicillin and his pain resolved. The bone scan had normalized after six months. We review the previous literature regarding syphilitic bone pain and periostitis. We discuss the importance of considering syphilis in the differential diagnosis of any sexually active adult presenting with bone pain, and highlight the usefulness of isotope bone scans in clarifying the clinical picture.