Search

Background: The fact that both Hollister-Stier and Allergopharma ceased the production of penicilloyl-polylysine (PPL) and minor determinant mixture (MDM) in 2004 is severely hampering the diagnosis of β-lactam hypersensitivity and may produce negative consequences. Objective: To assess the contribution of skin testing with benzylpenicillin to the diagnosis of immunoglobulin E-mediated hypersensitivity to penicillins, in order to determine how much such testing could compensate for PPL and MDM unavailability. Methods: We selected patients with histories of immediate reactions to penicillins and positive results to skin tests for one or more penicillin reagents (PPL, MDM, or benzylpenicillin), one or more semi-synthetic penicillins (ampicillin, amoxicillin, or piperacillin), or both. Results: A total of 300 patients were selected, 105 in the French center and 195 in the Italian centers. Amoxicillin and ampicillin were the main responsible drugs. The most common clinical manifestation was anaphylaxis. The reagents most frequently positive to skin tests were amoxicillin (188, 62.7%), ampicillin (151, 50.3%), and benzylpenicillin (111, 37.0%). Among the 300 subjects, 113 (37.7%) were positive only to semi-synthetic penicillins, 109 (36.3%) to both semi-synthetic penicillins and the classic penicillin reagents, and 78 (26.0%) only to the latter. In the last group, 64 (21.3% of the 300 subjects) were positive only to PPL and/or MDM and 14 (4.7%) to benzylpenicillin, of whom 8 (2.7%) were positive only to the latter. Conclusions: Skin testing with benzylpenicillin can partially compensate for PPL and MDM unavailability. Moreover, it can slightly increase the allergologic workup’s sensitivity and therefore reduce the number of potentially dangerous challenges. [ABSTRACT FROM AUTHOR]

Background Several studies have shown that skin tests are useful tools for the diagnosis of iodinated contrast medium (ICM) allergy, but the real number of false negative results is not known. Objective To evaluate the negative predictive value of ICM skin tests. Material and Methods One hundred and fifty-nine patients tested in our department because of a previous ICM reaction over the last 9 years were called and asked standardized questions about ICM re-exposure. Results Twenty-nine patients had been re-exposed to ICM. There were 20 (69.0%) females and the median age was 55 (34–60) years. The median time interval between the reaction and skin testing was 11.9 (1.6–21.5) years. Twenty-four patients (82%) had an immediate reaction, four a non-immediate (13.8%) reaction and no data were available for one patient. Two patients had positive ICM skin tests previously and were re-exposed to a negatively skin-tested ICM and did not react. Only two patients presented a mild reaction during ICM re-injection: one immediate (generalized urticaria lasting for 3 days) and one non-immediate maculopapular reaction. The patient with urticaria was re-tested and re-challenged (negative). The other patient was unable to return for re-testing. Conclusion Skin testing for ICM hypersensitivity has a negative predictive value of 96.6% (95% CI: 89.9–103.2) and none of the reactions in skin-test-negative patients were severe. Multi-centric large surveys are still needed for confirmation. Cite this as: S. Caimmi, B. Benyahia, D. Suau, L. Bousquet-Rouanet, D. Caimmi, P.-J. Bousquet and P. Demoly, Clinical & Experimental Allergy, 2010 (40) 805–810. [ABSTRACT FROM AUTHOR]

To cite this article: Demoly P, Romano A, Botelho C, Bousquet-Rouanet L, Gaeta F, Silva R, Rumi G, Rodrigues Cernadas J, Bousquet PJ. Determining the negative predictive value of provocation tests with beta-lactams. Allergy 2010; 65: 327–332. Background: The beta-lactam allergic work-up is mostly standardized. However, the negative predictive value of drug provocation tests is not yet well established. Method: A historical-prospective multicentre cohort study was conducted in four centres (one in France, one in Portugal, two in Italy) to assess the negative predictive value of provocation tests with beta-lactams in patients initially tested for a suspicion of drug allergy/hypersensitivity. Patients were contacted at least 6 months after the work-up, between 2003 and 2007. A new allergic work-up was proposed to reacting patients. Results: Among the 457 patients included, 365 (79.9%) were followed up (159 [79.1%] from France, 153 [82.7%] from Italy and 53 [74.6%] from Portugal). Only 118 (25.8%) were re-exposed to the negatively tested beta-lactam. Nine (7.6%) reported a non-immediate (occurring more than 1 h after drug administration) reaction: five urticaria, three exanthema and one undefined cutaneous reaction. None were severe. Only four accepted a re-challenge, negative in two cases and positive in the two others. The negative predictive value was 94.1% (89.8–98.3) (111 out of 118 patients). Conclusion: Although the negative predictive value of drug provocation tests may not be 100%, none of the false negative patients experienced a life-threatening reaction. This should reassure doctors who might hesitate to prescribe beta-lactams, even in patients with negative allergic work-ups. [ABSTRACT FROM AUTHOR]

Background: Skin prick testing is the standard for diagnosing IgE-mediated allergies. A positive skin prick reaction, however, does not always correlate with clinical symptoms. A large database from a Global Asthma and Allergy European Network (GA2LEN) study with data on clinical relevance was used to determine the clinical relevance of sensitizations against the 18 most frequent inhalant allergens in Europe. The study population consisted of patients referred to one of the 17 allergy centres in 14 European countries ( n = 3034, median age = 33 years). The aim of the study was to assess the clinical relevance of positive skin prick test reactions against inhalant allergens considering the predominating type of symptoms in a pan-European population of patients presenting with suspected allergic disease. Methods: Clinical relevance of skin prick tests was recorded with regard to patient history and optional additional tests. A putative correlation between sensitization and allergic disease was assessed using logistic regression analysis. Results: While an overall rate of ≥60% clinically relevant sensitizations was observed in all countries, a differential distribution of clinically relevant sensitizations was demonstrated depending on type of allergen and country where the prick test was performed. Furthermore, a significant correlation between the presence of allergic disease and the number of sensitizations was demonstrated. Conclusion: This study strongly emphasizes the importance of evaluating the clinical relevance of positive skin prick tests and calls for further studies, which may, ultimately, help increase the positive predictive value of allergy testing. [ABSTRACT FROM AUTHOR]

Background: Skin prick testing is the standard for diagnosing IgE-mediated allergies. However, different allergen extracts and different testing procedures have been applied by European allergy centres. Thus, it has been difficult to compare results from different centres or studies across Europe. It was, therefore, crucial to standardize and harmonize procedures in allergy diagnosis and treatment within Europe. Aims: The Global Asthma and Allergy European Network (GA²LEN), with partners and collaborating centres across Europe, was in a unique position to take on this task. The current study is the first approach to implement a standardized procedure for skin prick testing in allergies against inhalant allergens with a standardized pan-European allergen panel. Methods: The study population consisted of patients who were referred to one of the 17 participating centres in 14 European countries ( n = 3034, median age = 33 years). Skin prick testing and evaluation was performed with the same 18 allergens in a standardized procedure across all centres. Results: The study clearly shows that many allergens previously regarded as untypical for some regions in Europe have been underestimated. This could partly be related to changes in mobility of patients, vegetation or climate in Europe. Conclusion: The results of this large pan-European study demonstrate for the first time sensitization patterns for different inhalant allergens in patients across Europe. The standardized skin prick test with the standardized allergen battery should be recommended for clinical use and research. Further EU-wide monitoring of sensitization patterns is urgently needed. [ABSTRACT FROM AUTHOR]