Skin testing in gadolinium allergy: 2 case reports

Drug provocation tests (DPTs) of contrast media: Useful or not useful? - A narrative review

Drug provocation tests (DPTs) are also used in some patients with a history of a contrast medium (CM)-hypersensitivity reaction. Since the use of contrast agents requires special knowledge that is present in radiology but not necessarily in allergology, this overview should close the knowledge gaps. The literature, and the package inserts of the industry dealing with DPTs in contrast hypersensitivity reactions was analyzed and the results presented. Historical analyses revealed that provocation tests were already done in the past, and called pre-testing. Due to disadvantages, this diagnostic tool was abandoned. A few years later, DPT was introduced as an innovative diagnostic procedure. The DPT has the 3 main disadvantages: a missing standardization, patients at risk (such as compromised renal function) are rarely taken into account, and a negative DPT does not exclude a subsequent CM reaction. DPTs (formerly called pre-testing) are a well-known method for diagnosing CM-related hypersensitivity reactions. Since the disadvantages of this diagnosis outweigh the advantages, we propose replacing DPT with routine contrast-enhanced imaging examination in radiology.

Hypersensitivity to gadolinium-based contrast

PURPOSE OF REVIEW

The use of contrast media is increasing in recent decades. Although gadolinium-based contrast agents (GBCAs) are generally well tolerated, adverse reactions, including hypersensitivity reactions (HSRs), although infrequent, may occur. It is important to perform a thorough allergological evaluation in patients with suspected GBCA-HSRs to avoid potentially serious reactions in subsequent exposures.

RECENT FINDINGS

Data on GBCA-HSRs are scarce. Most published articles dealing with skin tests and drug provocation tests (DPTs) with GBCAs are case series and small cohorts. Controversies exist about the role of premedication for preventing HSRs on subsequent exposures. Selection of well tolerated alternatives is based on potential cross-reactivity among GBCAs; however, the extent of cross-reactivity among them remains unclear.

SUMMARY

As premedication is not useful because breakthrough reactions are frequent in patients with GBCA-HSRs in subsequent exposures, an allergological evaluation is required. Available data suggest a high negative predictive value of skin tests, being crucial for guiding the selection of an alternative GBCA. However, DPTs are still necessary to confirm or exclude the diagnosis or find alternative GBCAs. Cross-reactivity is high among GBCAs belonging from the same group, mainly among macrocyclic compounds, so this must be taken into account for selecting alternatives.

Contrast Medium Hypersensitivity: A Large Italian Study with Long-Term Follow-Up

Hypersensitivity reactions (HRs) to contrast media (CM) are a major problem. We compared differences of HRs to iodinated contrast media (ICM) versus gadolinium-based contrast media (GBCM), collecting data on prevalence, type, latency and severity. Secondly, the predisposition to perform new contrast tests, use of premedication and possible appearance of new reactions were explored in a long-term follow-up of 5 years. Clinical data, comorbidities, skin test (ST) results, re-exposure to CM procedures with any new reactions, premedication and CM used were collected. In a retrospective single-center study, 350 patients with mild to moderate HRs were enrolled. Asthma, food allergy, non-allergic drug hypersensitivity and neurologic disease were significantly more frequent in patients with HRs to GBCM compared to the high evidence of cardiovascular disease and history of cancer in patients with HRs to ICM. A marked delay in performing STs was reported by patients with negative results (66 months, p < 0.01). Iomeprol, iopamidol and gadobenic acid were the culprit CM most involved in HRs in patients with positive STs. During follow-up, 7.1% of responders reported new HRs to CM despite negative STs, premedication and infusion of alternative CM in most cases.

Hypersensitivity to Gadolinium-Based Contrast Media

Gadolinium-based contrast agents (GBCAs) are frequently used in magnetic resonance imaging (MRI) examinations to increase sensitivity in diagnoses. Recently, an increase in the description of hypersensitivity reactions to GBCAs has been detected. We performed research in PubMed, PubMed, SCOPUS, and EMBASE until September 2021, searching for studies regarding immediate and delayed hypersensitivity reactions to gadolinium-based contrast agents in which an allergy study was performed. The initial research identified 149 articles written in English. After excluding articles duplicated and articles that had irrelevant designs, 26 articles were included. Finally, 17 studies concerning immediate reactions, six studies concerning non-immediate reactions, and three concerning both that performed allergy evaluations were selected. In the review, we analyzed the characteristics of immediate and delayed reactions and the results of the allergy study and cross-reactivity. Skin tests seem to have acceptable accuracy, but drug provocation tests are still needed when skin tests are negative o to find alternative agents. Although cross-reactivity patterns are not well established, cross-reactivity seems to exist among macrocyclic agents. Notwithstanding, the number of patients analyzed is low and further studies are required. A management algorithm is suggested.

Skin Test Results and Cross-Reactivity Patterns in IgE- and T-Cell-Mediated Allergy to Gadolinium-Based Contrast Agents

Allergies to gadolinium-based contrast agents (GBCAs) are rare and manifest usually as an immediate drug hypersensitivity reaction (DHR), compatible with an immunoglobulin E (IgE)-mediated mechanism. Although the molecular structures of GBCA show some similarities and are either linear or macrocyclic, the frequency and pattern of cross-reactivity remain unclear. However, cross-reactivity has been described. The aim of this investigation was to assess cross-reactivity in patients with GBCA allergy based on skin tests and exposure. We retrospectively evaluated a total of 28 cases with a proven allergy to a GBCA, including 11 from the database of the allergy division of the Inselspital, Bern and 17 published cases from the literature, retrieved with a PubMed-MEDLINE search. The majority of cases were immediate DHR, with 8/11 cases from the database (72.7%) and 16/17 published cases (94.1%). In both groups macrocyclic GBCA were most often identified as causative drugs. A cross-reactivity based on skin test results was found in 2 out of 11 database cases (18.2%) and in 6 out of 17 literature cases (35.3%). Cross-reactivity occurred within macrocyclic GBCA in 1/11 database cases and 3/17 literature cases, and included both macrocyclic and linear GBCA in 1/11 and 4/17 subjects. There was no cross sensitization among linear GBCA. Skin test-negative GBCA were well tolerated, even in cases with sensitization to linear and macrocyclic GBCA. Overall, cross-reactivity in GBCA allergy is rare (approximately 29%), and may occur among macrocyclic GBCA or in between macrocyclic and linear GBCA. IgE to linear GBCA seems to be rarely cross-reactive. Skin test is helpful in identifying safe alternatives, as no reaction to skin test-negative GBCA was observed.

Empiric Switching of Gadolinium-Based Contrast Agents in Patients With History of Previous Immediate Hypersensitivity Reaction to GBCA: A Prospective Single-Center, Single-Arm Efficacy Trial

BACKGROUND

Breakthrough hypersensitivity reactions (HRs) to gadolinium-based contrast agent (GBCA) occur in 40% of patients despite corticosteroid premedication. Other strategies to reduce HRs are not well studied.

OBJECTIVE

The aim of this study was to prospectively evaluate HR rate to GBCA among patients with history of HR to GBCA, empirically given an alternative GBCA prior to repeat administration.

MATERIALS AND METHODS

From September 2019 to September 2020, patients with prior HR to GBCA received 13-hour oral corticosteroid and diphenhydramine premedication prescription with switching of GBCA to gadoterate (previously unavailable at our institution before September 2019). Power analysis (α error, 0.05; β error, 0.80) determined 21 patients were required. Patients were evaluated under a quality assurance waiver from the institutional review board. A radiologist documented the nature of initial HR and inciting GBCA, premedication received, incidence, and severity of breakthrough HR.

RESULTS

After exclusions, we evaluated 26 patients with mild (92.3% [24/26]) or moderate (7.7% [2/26]) HR to gadobutrol (53.8% [14/26]), gadoxetate (3.8% [1/26]), and gadopentetate (3.8% [1/26]). In 38.5% (10/26), inciting GBCA was unknown but was likely gadobutrol or gadopentetate based on availability. There were 22 females. The mean patient age was 52.1 ± 15.8 years.From 27 gadoterate administrations, 59.3% (16/27) patients received corticosteroid and diphenhydramine premedication, 11.1% (3/27) received only diphenhydramine, and 29.6% (8/27) with no premedication.Hypersensitivity reaction rate after empiric switching to gadoterate was 3.7% (1 mild reaction; 95% confidence interval [CI], 0.09%-18.9%) overall with no difference in patients with (6.3% [1/16]; 95% CI, 0.15%-28.7%) or without (0%; [0/11] upper bound 95% CI, 25.0%) corticosteroid premedication.

CONCLUSIONS

In this prospective single-arm study, empirically switching GBCA to gadoterate in patients with prior HR to GBCA substantially reduced the expected rate of subsequent HRs in patients with and without the use of corticosteroid premedication.

IMPLICATIONS FOR PATIENT CARE

Empirically switching GBCAs, with or without the use of corticosteroid premedication, can substantially reduce the rate of hypersensitivity breakthrough reactions.

Gadolinium-Based Contrast Agents Hypersensitivity: A Case Series

Gadolinium-based contrast agents (GBCAs) are considered to be safe, although sometimes patients report a hypersensitivity reaction when undergoing magnetic resonance imaging (MRI). The mechanisms of these reactions and of the sensitization to GBCAs are still largely unknown. We describe four cases of patients who experienced immediate adverse reactions to GBCAs with a demonstrated cutaneous hypersensitivity suggesting an IgE-mediated mechanism.

Breakthrough Hypersensitivity Reactions to Gadolinium-based Contrast Agents and Strategies to Decrease Subsequent Reaction Rates: A Systematic Review and Meta-Analysis

Background Hypersensitivity reactions to gadolinium-based contrast agents (GBCAs) that occur despite corticosteroid premedication (breakthrough reactions) are not well understood. Purpose To determine the GBCA breakthrough reaction rate overall and according to GBCA class and to determine the effect of using an alternative GBCA or allergy skin testing on the risk of a breakthrough reaction. Materials and Methods In this systematic review and meta-analysis, MEDLINE (from 1946 to 2019), Embase (from 1947 to 2019), and the Cochrane Central Register of Controlled Trials (2019 only) were searched for patients with a breakthrough reaction to a GBCA who were undergoing repeat GBCA administration. Breakthrough reaction rates were determined with random-effects modeling and meta-regression. Secondary analyses of GBCA class, switching to an alternative GBCA, and allergy skin testing were assessed. Quality Assessment of Diagnostic Accuracy Studies 2 was used to determine risk of bias and applicability. Percentages are meta-regression results and do not directly reflect raw data. Results Of the 148 identified studies, 23 were included, encompassing 120 patients and 130 GBCA administrations. The overall breakthrough reaction rate was 39% (95% confidence interval [CI]: 30%, 49%; 37 of 103 administrations). Breakthrough reaction rates for macrocyclic (36%; 95% CI: 25%, 48%; 23 of 64 administrations) and protein-binding linear (31%; 95% CI: 1%, 94%; [one of seven administrations) GBCAs did not differ (P = .90). There were insufficient analyzable data for gadodiamide, gadoversetamide, and gadopentetate. Hypersensitivity reaction rate after switching GBCAs was 50% (95% CI: 21%, 79%; three of nine administrations) with and 71% (95% CI: 21%, 95%; four of five administrations) without corticosteroid premedication, which did not differ (P = .82 and P = .17, respectively) from the observed rate when using corticosteroid premedication and the same GBCA (36%; 95% CI: 26%, 48%; 37 of 84 administrations). Hypersensitivity reaction rate after allergy skin testing (17%; 95% CI: 7%, 29%; zero of 21 studies) did not differ when compared with use of the same agent with corticosteroid premedication (P = .10). Meta-analysis limitations were the small number of patients and the high risk of bias. Conclusion Patients with a prior hypersensitivity reaction to a gadolinium-based contrast agent (GBCA) often had breakthrough reactions. The effect of switching to an alternative GBCA or using allergy skin testing to decrease reaction risk lacked enough available data for meaningful comparisons. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Prince in this issue.

A rare case of acute respiratory distress syndrome caused by use of gadolinium-based magnetic resonance imaging contrast media

Gadolinium-based magnetic resonance imaging (MRI) contrast is generally considered to be stable and safe. Adverse reactions due to MRI contrast agents are classified into allergic-like reactions and physiological reactions. Acute respiratory distress syndrome (ARDS) caused by gadolinium-based MRI contrast is extremely rare. Due to the immediate and severe nature of ARDS, medical practitioners may seek after other aetiologies other than MRI-contrast-induced ARDS for patients' clinical manifestations such as acute-onset difficulty of breathing. It is crucial to keep in mind the possibility of ARDS after gadolinium injection, as missing the diagnosis leads to a high mortality. A clear clinical scenario of ARDS induced by gadobutrol (Gadovist, Bayer Inc., Toronto, Canada) was presented in our patient who did not develop symptoms of anaphylaxis. We successfully managed the patient with methylprednisolone and bilevel positive airway pressure ventilation and the patient was discharged in stable condition on day 6.