[Diagnosis of drug allergy. Role of specific IgE and IgG determination].

In the diagnosis of drug allergies, the anamnesis and, in some cases, prick tests are without doubt indispensable approaches but they are not always able to provide optimal prognostic levels. Moreover, prick tests are sometimes contraindicated owing to their potential danger. This study evaluated the diagnostic efficacy of a test in vitro--the assay of IgE- and IgG-specific (RAST)--for a group of 16 drugs in 88 patients referred for allergological consultancy after clinical manifestations attributable to the administration of a drug (30/88 cases) or more than one drug (58/88). Disorders had appeared at least one week after the start of drug treatment, an interval that is compatible with the development of an immune response. In 17/88 (19.3%) patients the in vitro test confirmed the presence of IGe and/or IgG against at least one of the drugs suspected in the anamnesis. In this series it was also found that there was a higher incidence of ADR in females (60/88) compared to males (28/88). Reactions to several drugs were more frequent than reactions to a single drug (58 cases vs 30). The association of ADR and the presence of other allergies in a particular individual was relatively rare (13/88 = 14.7%). These results confirm the value of RAST as a useful aid to improve the overall diagnosis of drug allergies and to make it safer.