title: Amoxicillin rash in patients with infectious mononucleosis: evidence of true drug sensitization.
abstract: BACKGROUND
  It hasn't been clearly understood yet whether sensitization to antibiotics, the virus itself or transient loss of drug tolerance due to the virus, is responsible for the development of maculopapular exanthems following amoxicillin intake in patients with infectious mononucleosis. We aimed to examine whether sensitization to penicillin developed among patients with skin rash following amoxicillin treatment within infectious mononucleosis.
  
  
  METHODS
  Ten patients were investigated for drug sensitization by lymphocyte transformation test and six patients were further tested by prick-, intradermal and patch tests employing the penicillin's main antigens.
  
  
  RESULTS
  Lymphocyte transformation test showed negative results with amoxicillin, while one patient had positive reaction to cefixime. Six patients with suspected sensitization to amoxicillin were then investigated by in vivo tests. Prick tests were negative in all six patients, but the intradermal tests showed positive reactions in four patients.
  
  
  CONCLUSIONS
  Our data demonstrate that in vitro testing is not sensitive enough in determining drug sensitization to penicillin. In vivo tests should be performed to detect sensitization and indeed with skin tests our results confirmed that sensitization to aminopenicillin may develop within infectious mononucleosis.
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary.
authors.forename: Katinka
authors.initials: K
authors.lastname: Ónodi-Nagy
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary.
authors.forename: Ágnes
authors.initials: Á
authors.lastname: Kinyó
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary.
authors.forename: Angéla
authors.initials: A
authors.lastname: Meszes
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary.
authors.forename: Edina
authors.initials: E
authors.lastname: Garaczi
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary ; Dermatological Research Group of the Hungarian Academy of Sciences, University of Szeged, Szeged, Hungary.
authors.forename: Lajos
authors.initials: L
authors.lastname: Kemény
authors.affiliation: Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Korányi fasor 6, Szeged, 6720 Hungary ; Dermatological Research Group of the Hungarian Academy of Sciences, University of Szeged, Szeged, Hungary.
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Bata-Csörgő
keywords: Amoxicillin; Drug tests; Infectious mononucleosis; Sensitization to antibiotics