Increased FDG uptake along dermatome on PET in a patient with herpes zoster

This is a 66-year-old female patient being treated for diffuse large B-cell lymphoma. She reported to her physician in late January 2012 with a left flank pruritic painful rash. She was diagnosed with herpes zoster and treated with antiviral medication. Her chemotherapy regimen was delayed due to the zoster infection. In March 2012, the patient underwent a PET/CT as a lymphoma surveillance scan prior to reinstituting the chemotherapy treatment. As an incidental finding, the PET showed increased metabolic activity in a dermatomal distribution along the left flank, which corresponded to the patient's zoster infection.