Acyclovir: A GUANOSINE analog that acts as an antimetabolite. Viruses are especially susceptible. Used especially against herpes.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Herpes Simplex: A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. (Dorland, 27th ed.)Herpes Genitalis: Infection of the genitals (GENITALIA) with HERPES SIMPLEX VIRUS in either the males or the females.Herpes Zoster: An acute infectious, usually self-limited, disease believed to represent activation of latent varicella-zoster virus (HERPESVIRUS 3, HUMAN) in those who have been rendered partially immune after a previous attack of CHICKENPOX. It involves the SENSORY GANGLIA and their areas of innervation and is characterized by severe neuralgic pain along the distribution of the affected nerve and crops of clustered vesicles over the area. (From Dorland, 27th ed)Herpes Labialis: Herpes simplex, caused by type 1 virus, primarily spread by oral secretions and usually occurring as a concomitant of fever. It may also develop in the absence of fever or prior illness. It commonly involves the facial region, especially the lips and the nares. (Dorland, 27th ed.)Herpesvirus 2, Human: A species of SIMPLEXVIRUS associated with genital infections (HERPES GENITALIS). It is transmitted by sexual intercourse and close personal contact.Simplexvirus: A genus of the family HERPESVIRIDAE, subfamily ALPHAHERPESVIRINAE, consisting of herpes simplex-like viruses. The type species is HERPESVIRUS 1, HUMAN.Valine: A branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.Foscarnet: An antiviral agent used in the treatment of cytomegalovirus retinitis. Foscarnet also shows activity against human herpesviruses and HIV.Ganciclovir: An ACYCLOVIR analog that is a potent inhibitor of the Herpesvirus family including cytomegalovirus. Ganciclovir is used to treat complications from AIDS-associated cytomegalovirus infections.Encephalitis, Herpes Simplex: An acute (or rarely chronic) inflammatory process of the brain caused by SIMPLEXVIRUS infections which may be fatal. The majority of infections are caused by human herpesvirus 1 (HERPESVIRUS 1, HUMAN) and less often by human herpesvirus 2 (HERPESVIRUS 2, HUMAN). Clinical manifestations include FEVER; HEADACHE; SEIZURES; HALLUCINATIONS; behavioral alterations; APHASIA; hemiparesis; and COMA. Pathologically, the condition is marked by a hemorrhagic necrosis involving the medial and inferior TEMPORAL LOBE and orbital regions of the FRONTAL LOBE. (From Adams et al., Principles of Neurology, 6th ed, pp751-4)Ointments: Semisolid preparations used topically for protective emollient effects or as a vehicle for local administration of medications. Ointment bases are various mixtures of fats, waxes, animal and plant oils and solid and liquid hydrocarbons.Herpes Zoster Ophthalmicus: Virus infection of the Gasserian ganglion and its nerve branches characterized by pain and vesicular eruptions with much swelling. Ocular involvement is usually heralded by a vesicle on the tip of the nose. This area is innervated by the nasociliary nerve.Prodrugs: A compound that, on administration, must undergo chemical conversion by metabolic processes before becoming the pharmacologically active drug for which it is a prodrug.GuanineStomatitis, Herpetic: Stomatitis caused by Herpesvirus hominis. It usually occurs as acute herpetic stomatitis (or gingivostomatitis), an oral manifestation of primary herpes simplex seen primarily in children and adolescents.Herpesvirus 3, Human: The type species of VARICELLOVIRUS causing CHICKENPOX (varicella) and HERPES ZOSTER (shingles) in humans.Keratitis, Dendritic: A form of herpetic keratitis characterized by the formation of small vesicles which break down and coalesce to form recurring dendritic ulcers, characteristically irregular, linear, branching, and ending in knoblike extremities. (Dictionary of Visual Science, 3d ed)Thymidine Kinase: An enzyme that catalyzes the conversion of ATP and thymidine to ADP and thymidine 5'-phosphate. Deoxyuridine can also act as an acceptor and dGTP as a donor. (From Enzyme Nomenclature, 1992) EC 2.7.1.21.Herpesvirus 1, Human: The type species of SIMPLEXVIRUS causing most forms of non-genital herpes simplex in humans. Primary infection occurs mainly in infants and young children and then the virus becomes latent in the dorsal root ganglion. It then is periodically reactivated throughout life causing mostly benign conditions.Administration, Oral: The giving of drugs, chemicals, or other substances by mouth.Administration, Topical: The application of drug preparations to the surfaces of the body, especially the skin (ADMINISTRATION, CUTANEOUS) or mucous membranes. This method of treatment is used to avoid systemic side effects when high doses are required at a localized area or as an alternative systemic administration route, to avoid hepatic processing for example.Chickenpox: A highly contagious infectious disease caused by the varicella-zoster virus (HERPESVIRUS 3, HUMAN). It usually affects children, is spread by direct contact or respiratory route via droplet nuclei, and is characterized by the appearance on the skin and mucous membranes of successive crops of typical pruritic vesicular lesions that are easily broken and become scabbed. Chickenpox is relatively benign in children, but may be complicated by pneumonia and encephalitis in adults. (From Dorland, 27th ed)Virus Shedding: The expelling of virus particles from the body. Important routes include the respiratory tract, genital tract, and intestinal tract. Virus shedding is an important means of vertical transmission (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Viral Plaque Assay: Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.Encephalitis, Varicella Zoster: Inflammation of brain tissue caused by infection with the varicella-zoster virus (HERPESVIRUS 3, HUMAN). This condition is associated with immunocompromised states, including the ACQUIRED IMMUNODEFICIENCY SYNDROME. Pathologically, the virus tends to induce a vasculopathy and infect oligodendrocytes and ependymal cells, leading to CEREBRAL INFARCTION, multifocal regions of demyelination, and periventricular necrosis. Manifestations of varicella encephalitis usually occur 5-7 days after onset of HERPES ZOSTER and include HEADACHE; VOMITING; lethargy; focal neurologic deficits; FEVER; and COMA. (From Joynt, Clinical Neurology, 1996, Ch 26, pp29-32; Hum Pathol 1996 Sep;27(9):927-38)Bell Palsy: A syndrome characterized by the acute onset of unilateral FACIAL PARALYSIS which progresses over a 2-5 day period. Weakness of the orbicularis oculi muscle and resulting incomplete eye closure may be associated with corneal injury. Pain behind the ear often precedes the onset of paralysis. This condition may be associated with HERPESVIRUS 1, HUMAN infection of the facial nerve. (Adams et al., Principles of Neurology, 6th ed, p1376)Arabinofuranosyluracil: A pyrimidine nucleoside formed in the body by the deamination of CYTARABINE.Skin Diseases, Viral: Skin diseases caused by viruses.Phosphonoacetic Acid: A simple organophosphorus compound that inhibits DNA polymerase, especially in viruses and is used as an antiviral agent.Idoxuridine: An analog of DEOXYURIDINE that inhibits viral DNA synthesis. The drug is used as an antiviral agent.Virus Activation: The mechanism by which latent viruses, such as genetically transmitted tumor viruses (PROVIRUSES) or PROPHAGES of lysogenic bacteria, are induced to replicate and then released as infectious viruses. It may be effected by various endogenous and exogenous stimuli, including B-cell LIPOPOLYSACCHARIDES, glucocorticoid hormones, halogenated pyrimidines, IONIZING RADIATION, ultraviolet light, and superinfecting viruses.Pharmaceutical Vehicles: A carrier or inert medium used as a solvent (or diluent) in which the medicinally active agent is formulated and or administered. (Dictionary of Pharmacy, 1986)Inosine Pranobex: An alkylamino-alcohol complex of inosine used in the treatment of a variety of viral infections. Unlike other antiviral agents, it acts by modifying or stimulating cell-mediated immune processes rather than acting on the virus directly.Double-Blind Method: A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.Recurrence: The return of a sign, symptom, or disease after a remission.Vidarabine: A nucleoside antibiotic isolated from Streptomyces antibioticus. It has some antineoplastic properties and has broad spectrum activity against DNA viruses in cell cultures and significant antiviral activity against infections caused by a variety of viruses such as the herpes viruses, the VACCINIA VIRUS and varicella zoster virus.Keratitis, Herpetic: A superficial, epithelial Herpesvirus hominis infection of the cornea, characterized by the presence of small vesicles which may break down and coalesce to form dendritic ulcers (KERATITIS, DENDRITIC). (Dictionary of Visual Science, 3d ed)