Herpes simplex virus encephalitis during treatment with etanercept.

Tumor necrosis factor alpha (TNF-α) inhibitors are widely used for the treatment of various inflammatory conditions. They are associated with an increased risk for infections. We report a case of herpes simplex virus type 1 (HSV-1) encephalitis in a patient receiving etanercept and review the literature on TNF-α and TNF-α inhibitors, and their importance in the pathophysiology of herpes simplex encephalitis.