title: Sensitivity and specificity of skin tests in the diagnosis of clarithromycin allergy.
abstract: BACKGROUND
  Clarithromycin is one of the most frequently prescribed oral macrolidic antibiotics in the pediatric population. Suspected adverse reactions to clarithromycin have been frequently described by parents of children examined in pediatric allergy units, but there is a lack of reliable methods available in detecting the presence of specific IgE antibodies.
  
  
  OBJECTIVE
  To investigate the prevalence of a clarithromycin allergy in children seen in a pediatric allergy unit using standardized skin tests and oral provocation tests (OPTs).
  
  
  METHODS
  Sixty-four children were referred with a history of a clarithromycin-associated adverse drug reaction. All these children underwent skin tests and OPTs. The nonirritating intradermal skin test concentration for clarithromycin was determined in a control group of 18 children who had tolerated clarithromycin in the previous month.
  
  
  RESULTS
  The threshold nonirritating intradermal concentration was established at the 10:2 dilution (0.5 mg/mL). Nine of the 64 children had an immediately positive intradermal response to the 10:2 dilution and only 1 child to the 10:3 dilution (0.05 mg/mL). None had positive skin prick test results or delayed skin responses to intradermal tests. Four of 64 children (6%) with previously described adverse reactions due to clarithromycin intake had a positive OPT reaction. When we correlated the intradermal skin test results to the OPT results, intradermal test sensitivity and specificity were 75% and 90%, respectively.
  
  
  CONCLUSIONS
  Intradermal tests seem to be useful in allergologic workup in children with suspected clarithromycin hypersensitivity and may help reduce the need for OPTs.
authors.affiliation: Paediatric Allergy and Immunology Unit, A. Meyer Children's Hospital, Department of Paediatric, University of Florence, Florence, Italy. f.mori@meyer.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Mori
authors.forename: Simona
authors.initials: S
authors.lastname: Barni
authors.forename: Neri
authors.initials: N
authors.lastname: Pucci
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Rossi
authors.forename: Chiara
authors.initials: C
authors.lastname: Azzari
authors.forename: Maurizio
authors.initials: M
authors.lastname: de Martino
authors.forename: Elio
authors.initials: E
authors.lastname: Novembre
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D001985:Bronchial Provocation Tests; D002648:Child; D002675:Child, Preschool; D017291:Clarithromycin / Q000009:adverse effects*; D004342:Drug Hypersensitivity / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007558:Italy; D008297:Male; D012680:Sensitivity and Specificity; D012882:Skin Tests
chemical_list: D000900:Anti-Bacterial Agents; D017291:Clarithromycin