Anaphylaxis to gadobenate dimeglumine (Multihance): a case report.

BACKGROUND: Gadolinium chelates are relatively safe contrast media used in MRI. Immediate severe adverse effects are exceptionally rare and mostly concern mild anaphylactoid reactions. We report a case of anaphylaxis to gadobenate dimeglumine (Gd-BOPTA, Multihance), a gadolinium-based contrast agent. METHODS: A 32-year-old female patient with a personal history of multiple sclerosis, while undergoing an MRI scan, developed bronchospasm and acute urticaria with diffuse giant pruritic plaques in the first minute of Gd-BOPTA infusion. The procedure was cancelled and acute treatment of the reaction took place. The patient reported 2 additional MRI scans with definite use of unknown contrast media in the past 2 years without any adverse effect. Blood samples were obtained 2 and 48 h after the reaction for measurement of serum tryptase concentration (Pharmacia Diagnostics, Uppsala, Sweden). Skin prick tests and intradermal tests were performed using 1:1,000, 1:100 and 1:10 dilution of the offending agent and alternative gadolinium-based agents [gadodiamide (Omniscan) and gadoteric acid (Dotarem)]. A group of 10 nonatopic individuals who underwent the same skin testing comprised the control group. RESULTS: Tryptase concentration was highly elevated 2 h after the reaction (21 microg/l) compared with that at 48 h (3 microg/l). Skin prick tests in our patient were all negative, while intradermal testing with 0.03 ml of 1:100 and 1:10 preparations of Multihance showed a definite positive wheal-and-flare reaction. Skin tests to the alternative agents showed no response. In the control group, all performed tests were negative. CONCLUSION: We report the first case of an allergic reaction to gadobenate dimeglumine. Besides, skin testing seems to be a precious diagnostic tool which, if positive, strongly suggests a mast cell-mediated underlying mechanism.

Exhaled nitric oxide, bronchial hyperresponsiveness and spirometric parameters in patients with allergic rhinitis during pollen season.

Allergic rhinitis and asthma share common epidemiological features and inflammatory processes. The aim of the present study was to document the influence of natural allergen exposure in exhaled NO (eNO) and in spirometric parameters of patients with seasonal allergic rhinitis(SAR) and to investigate the differences among subjects with positive versus negative bronchial provocation to metacholine(BPMch).Twenty-six non-smoking patients (13F/13M; mean age 28.4ys) with a documented history of SAR, 15 healthy, non-atopic(6F/9M; mean age 37.1ys) and 6 non-symptomatic atopic subjects (3F/3M; mean age 36.5ys) were studied. At the first visit during pollen season each subject filled symptom-score card, underwent eNO and nasal NO (nNO) measurements and spirometry. BPMch was performed within the next 10 days. At the second visit out of pollen season, all measurements but BPMch were repeated. Control subjects underwent eNO and nNO measurements.eNO was significantly increased during pollen season in BPMch positive vs BPMch negative(46.22±32.60 vs 17.81±12.67, p=0.014) and vs non-atopic controls(11.40±5.84, p<0.001) as well as atopic controls(13.56±5.34, p=0.001). No difference was detected out of pollen season in both patients' groups. nNO values were increased only in BPMch(+) group compared to both control groups in pollen season (vs non-atopics p=0.002, vs atopics p=0.002) and only vs non-atopics out of season, p=0.004. Regression analysis has shown that the difference in FEF25-75 values (off season-in season) is a predictor of positive BPMch .eNO is markedly increased in BPMch patients with allergic rhinitis while mid-expiratory flow may represent an early marker of lower airway involvement in respiratory allergy.

Allergy skin testing in predicting adverse reactions to fluorescein: a prospective clinical study.

PURPOSE: To evaluate allergy skin testing as a diagnostic tool of adverse reactions to fluorescein and whether allergy and previous sodium fluorescein angiography (SFA) act as predisposing factors. METHODS: Patients with adequate indication for fluorescein angiography and normal skin responsiveness were subjected to allergy skin-prick and intradermal tests for fluorescein, followed by SFA. During SFA, adverse reactions were monitored and classified as mild, moderate or severe. Previous SFAs and adverse reactions as well as the presence of atopy were also registered. RESULTS: One thousand and thirty-seven patients were enrolled in the study and 1284 SFAs were executed. Forty-four patients (4.3%) developed 55 adverse reactions; among them 50 (3.8%) were mild, three (0.2%) moderate and two (0.16%) severe. None of the reactors produced positive skin tests to fluorescein. Patients with atopy and previous SFAs were not more susceptible to adverse reactions. CONCLUSION: The vast majority of adverse reactions to fluorescein are mild and not attributed to immunological mechanisms. Allergy skin tests cannot predict non-immunological reactions but their utility remains substantial in predicting anaphylaxis during SFAs and must be performed in patients reporting risk factors in their past medical history.