Knobil K, \Viener C, Zenilm:m J. Herpes simplex infections in the critical care selling. J Intensive Care Med 1997;12:93--103.Infcctions caused by herpes simplex virus (lISV) l}'pes 1 and 2 are widely prevalent and usually asymptomatic. In the immunocompromised or severely ill patient, however, lISV can cause a \'ariel}' of mucosal and systemic syndromes. Organ systems most susceptible include the gastrointestinal tract,lungs, and the central neo'ous system. Systemic dissem· inated disease may also occur. With the exception of herpes encephalitis, clinical diagnosis of serious IISV infections is difficult, because it occurs in hosts who are susceptible to a wide range of infectious and metabolic problems. "'e review the presenting syndromes of IISV infection in the critically ill patient, and outline current concepts for diagnosis and treatment.From the°Dh'ision of Pulmonary and Critical Care Medicine, and the tDh'ision