NTRODUCTION
HSV-1 is a member of the Alphaherpesvirinae subfamily. Herpes simplex virus (HSV) infections are very common; the seroprevalence in adults is about 80 to 90% for HSV-1. HSV infection in immunocompetent individuals normally does not cause major health problems. HSV-1 is commonly associated with herpes outbreaks of the face known as cold sores or fever blisters. HSV reactivation in the central nervous system can occur and might cause a wide range of clinical symptoms from mild meningitis (Mollaret’s) to severe encephalitis with a mortality rate of up to 70% in the absence of therapy. HSV-1 and HSV-2 differ in their behaviour in the central nervous system (CNS). HSV-1 reactivation is the most frequent cause of viral encephalitis, a disease with a dire prognosis in the absent of early specific therapy. Primary infection of neonates or reactivation of HSV in immunocompromised individuals can be associated with a higher incidence of meningitis, severe encephalitis, and dangerous eye infections. In addition, patients with atopic eczema are prone to widespread cutaneous herpes simplex infection.