Diagnostic approach to hypersensitivity reactions to iodinated contrast media: a single-center experience on 98 patients.

Summary: Adverse reactions to iodinated contrast media (ICM) are reported in 1%-3% of diagnostic procedures. They represent a relevant problem involving patients' safety as well as relevant costs for healthcare systems. Premedication with antihistamines and corticosteroids is still widely used, but evidence of its efficacy is lacking and there is a risk for under-estimation of possible severe adverse reactions to ICM in those who undergo premedication. Data from 98 patients with a previous reaction to ICM that consecutively referred to our unit between 2015 and 2018 were retrospectively analyzed. They underwent an allergologic workup comprehending skin tests and drug provocation tests (DPT) with ICM. The skin test showed a very high negative predictive value (NPV) compared to DPT in patients with a previous immediate adverse reaction, while the NPV in patients with a previous delayed adverse reaction was lower. After completion of the allergologic workup, 94 patients (95.9%) could tolerate a DPT with the culprit or alternative ICM. Subsequently, 90 patients were reached by phone to assess if they had been re-exposed to ICM for radiologic procedure. Thirty-nine patients had been re-exposed, without any premedication in 13 cases: 12 of them had tolerated the ICM, while one reacted again despite a negative DPT with the same ICM. Overall, the NPV of this protocol was elevated (92.3%) for patients undergoing DPT and subsequent exposure to the same ICM in a real-life setting. Collaboration between the prescribing physician, the radiologist and the allergist, and an accurate allergologic workup are essential to ensure maximum safety for the patient.

Aspirin challenge/desensitisation before coronary stenting in subjects with history of hypersensitivity. A pragmatic approach.

BACKGROUND: Aspirin hypersensitivity may represent a major problem in patients with ischemic coronary disease who need a stenting procedure. In those patients, clinically unsettled reasonably quick desensitisation procedures are needed. In our study we attempted to select the most suitable procedure on the basis of characteristics and severity of ASA hypersensitivity. METHODS: Thirty patients with a history of mild reactions to anti-inflammatory doses of aspirin (> 325 mg) were considered at low risk and underwent a tolerance test in 5 steps. Thirty-one patients, with a history of severe reactions to anti-platelet doses of aspirin 0 mg) underwent a slow desensitisation in 12 steps, reaching a cumulative dose of 150 mg ASA in 220 minutes. RESULTS: In the first group, 29 patients tolerated the challenge. One developed urticaria, thus underwent challenge/desensitisation and achieved tolerance. In the second group, 3 patients did not tolerate the procedure and had to discontinue. CONCLUSION. Our approach to aspirin hypersensitivity in patients needing coronary stenting, based on a severity stratification, allowed to achieve an effective tolerance to aspirin in the majority of subject in a reasonable short time.

[Recent findings in the pathogenesis of bronchial asthma]. / Recenti acquisizioni sulla patogenesi dell'asma bronchiale.

The latest discoveries about the pathogenesis of asthma are reported with emphasis on new data concerning the discovery of factors capable of controlling the production of IgE antibodies. The mechanisms implicated in early and late phase reactions are then discussed. In addition, the relationships between neuropeptides and chronic inflammation are described. Finally, the role of active substances produced by the bronchial epithelium on the induction and maintenance of bronchial inflammation is reviewed.