title: Allopurinol as a potential therapeutic agent for recurrent herpes labialis.
abstract: Recurrent herpes labialis (RHL) occurs in up to 40% of the population. Although the disease is usually self-limiting, patients seek treatment because of the significant pain and visibility of the lesion. Xanthine oxidase inhibitors (XOI) have been reported to have a potent antiviral effect against influenza-A virus. We examined the effect of the systemic xanthine oxidase inhibitor, allopurinol, on RHL duration of illness, severity of symptoms, number and frequency of recurrence during a 4-year follow up period in Egyptian patients. Duration of illness was shortened by about 25%, early disappearance of pain and other symptoms occurred. Also, aborted episodes were noticed when allopurinol was given just after beginning of common colds, at the prodromal stage of RHL or during severe stress conditions. Patients receiving 3 courses of treatment had markedly decreased recurrences during the follow up period. Ex vivo experiments to examine virus-induced plaque formation on Vero cells in the absence or presence of different concentrations of the drug could not prove any direct anti herpetic effect of the drug. However, allopurinol seems to be safe and effective in reducing duration of RHL and to abort lesion or prevent its appearance in treated patients even when they experience immunosuppressive conditions.
authors.affiliation: Department of Medical Microbiology & Immunology, Faculty of Medicine, Mansoura University, Mansoura, Egypt. mfarash@hotmail.com
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: El-Farrash
authors.forename: Jilan M
authors.initials: JM
authors.lastname: Youssef
authors.forename: Shaymaa E
authors.initials: SE
authors.lastname: El-Mongy
mesh_terms: D000293:Adolescent; D000328:Adult; D000493:Allopurinol / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D002522:Chlorocebus aethiops; D004791:Enzyme Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D005260:Female; D006560:Herpes Labialis / Q000188:drug therapy*; D018259:Herpesvirus 1, Human / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D055502:Secondary Prevention; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D000493:Allopurinol