Le correlazioni clinico-anamnestiche e i risultati dei test cutanei allergodiagnostici nelle reazioni avverse cutaneo-mucose ad antibatterici sistemici

Background: diagnosis of adverse drug reactions (ADR) is not easy and the correct clinical anamnestic approach represents the first step. This allows you to define the imputability criterion, ie the causal link between the drug and the skin manifestations induced by it. In order to optimize this approach, six classes of clinico-anamnestic correlations (CAC) were recently identified by us: "certain" "very likely," "likely," "dubious," "no correlation", "indeterminable". The second diagnostic step includes the perfor-mance of allergogical skin tests (AST) (patch test, prick test and intradermal test), although their reliability is influenced by technical factors. Objectives: i) to validate the proposed criteria to define CAC classes through AST performed in patients with skin ADR from systemic antibacterials; ii) to determine possible correlations between positive reactions to AST, ADR clinical morphology and drug involved. Materials and methods: we retrospectively examined clinical data, medical history and AST results performed in 451 subjects (292 F, 159 M) with skin ADR arised during therapy with systemic antibacterials. Patients were distributed in the six classes of CAC; positive reactions to AST within each of classes were identified. Finally AST positive reactions in relation to ADR morphology and type of drug involved were analyzed. Results: in 32.2% of cases were identified 1 of the 3 first CAC, especially "very likely" (26.8%). In the remaining patients the most frequent CAC was "indeterminable" (53.2%). 18.1% of the subjects had positive reactions to AST; the most frequent positive AST was the intradermal test (65.9%). CAC with higher prevalence of positive reactions were "certain" (29.4%) and "very likely" (24.8%), with statistical significance compared to that observed in other CAC (p=0.01). Positive reactions to AST were more frequent in ADR with IgE-mediated pathogenesis and caused by betalactams than in cell-mediated ADR. Conclusions: our data seem to validate the criteria proposed by us to define the CAC in skin ADR induced by antibacterials. The large number of subjects included in the CAC "indeterminable" confirms the difficulty to clinical anamnestic approach in such patients, especially in cases of long lasting past ADR. © Monte Meru Editrice.