Accuracy in diagnosis of allergy to beta lactam (Critical Care)

There are a large number of patients labelled as allergic to drugs commonly used in clinical practice without having been studied and based only on clinical history. This creates a major health resource problem, having to use alternative treatments, in many cases with higher cost.We would like to describe our experience to reach a reliable diagnosis to prove allergy to anti-infective drugs. Subjects referred for the assessment of any history of immediate drug allergy reaction (2001-2010) had not only symptoms reactions limited to the skin (urticaria, erythema, and angioedema), but also confusion, collapse, unconsciousness, hypotension, diaphoresis, vomiting, presyncope, dyspnea, stridor, wheeze, chest/throat tightness, nausea/vomiting, and abdominal pain. Diagnosis was supported by in vivo testing including Skin Test (ST) such as Skin Prick and intradermal Test. Whether STs were negative, a single-blind challenge was performed by increasing doses of the suspected drug until the usual daily dose was administered. Results show that a total of 3,426 studies with anti-infective drugs were performed with 231 positive cases (7%). Only 3% (114) patients were not studied by refusal or rejected. The most problem group of antibiotics was the penicillin, including aminopenicillins.