The Great Imitator Strikes Again

Introduction: 

Periostitis is a well-described manifestation of acquired syphilis uncommonly seen in clinical practice. We review a case of syphilis in a man with a history of HIV and treated lymphoma who presented with severe tibial pain. The incidence of syphilis in MSM continues to increase and early recognition and management of unusual presentations has important individual and public health implications.

Case Description: 

A 44 year old male presented with the sole complaint of a four day history of progressive, severe unilateral shin pain. His medical history was significant for AIDS on antiretroviral therapy with a recent CD4 T-lymphocyte count of 125 cells/mm³, and diffuse large B cell lymphoma with successful treatment completion 1 year prior.

Exam was remarkable for the absence of fever, rash, oral lesions or joint swelling and the presence of exquisite tenderness to palpation of the proximal right tibia. A tibia plain film showed an area of focal periosteal bone. MRI showed patchy bone marrow edema with adjacent periosteal and soft tissue edema, raising concern for an atypical infection or infiltrative process such as lymphoma.

One week later he developed a rash consisting of multifocal erythematous, nontender macular lesions. Serology revealed a RPR titer  >1:256 and CSF evaluation demonstrated a reactive VDRL at 1:1. Therapy for neurosyphilis was completed. His tibial pain and rash resolved with treatment and follow-up serology has shown an appropriate response.

Discussion:  

Syphilis has long been regarded as the great imitator and it is important for contemporary practitioners to be aware of unusual presenting scenarios for this important public health threat.  Since MSM account for the majority of primary and secondary syphilis cases in the US, with high rates of HIV co-infection, early recognition of syphilis has the potential to reduce transmission of both conditions.