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Diagnostic tests in respiratory medicine
Published in Vibeke Backer, Peter G. Gibson, Ian D. Pavord, The Asthmas, 2023
Vibeke Backer, Peter G. Gibson, Ian D. Pavord
When a skin prick test is clearly positive and in accordance with the history, specific IgE or provocation testing may add no more information than would repetition of the skin test on the other arm. A false-negative result, either smaller size of the wheal or completely negative, could happen in the case of use of antihistamine. On the other hand, a false positive response could be due to dermographism, in which case all tests would be positive including the negative control. When there is doubt about the significance of a skin test, another type of test can be added, providing the result is relevant to any therapeutic decision. If a confirmatory test is needed, specific measurement of IgE is preferable to allergen provocation because it is less expensive, safer and more precise. In particular, the adverse reaction of the allergen provocation test, with increased asthma for 3 weeks after the allergen bronchial challenge, makes it less attractive.
Diagnosis of Drug Eruptions: Clinical Evaluation and Drug Challenge
Published in Kirsti Kauppinen, Kristiina Alanko, Matti Hannuksela, Howard Maibach, Skin Reactions to Drugs, 2020
Kristiina Alanko, Kirsti Kauppinen
Since oral challenge always includes the hazard of an unexpectedly strong reaction, many authors recommend that its use be restricted to absolutely essential situations.13,14 In our experience, a drug provocation is safe when performed with caution. If the reaction has been severe, i.e., anaphylaxis, toxic epidermal necrolysis, Stevens-Johnson syndrome, or a systemic lupus erythematosus-like reaction, a provocation test should not be performed. Also, if the rash has been complicated by blood dysfunctions, e.g., allergic thrombocytopenia, re-exposure is not advisable.4,8 Anaphylactoid (pseudo-allergic) reactions may not be reproduced like the true allergic reactions.
β-Lactam Allergy
Published in Firza Alexander Gronthoud, Practical Clinical Microbiology and Infectious Diseases, 2020
If the patient has an infection for which the optimal treatment is with a β-lactam agent, then obtain informed consent from the patient and perform β-lactam sensitivity testing unless the patient had a very severe allergic reaction. Patients should be directly observed for up to 1 hour when being challenged with a provocation test. Non-severe reaction: Perform β-lactam provocation testModerate severe reaction: Skin test; if negative, perform β-lactam provocation testVery severe reaction: Penicillin allergy testing not indicted
Hypersensitivity reactions to biologics in children
Published in Expert Opinion on Biological Therapy, 2023
Leticia de Las Vecillas, Davide Caimmi, Ghislaine Annie Clarisse Isabwe, Ricardo Madrigal-Burgaleta, Ozge Soyer, Luciana Tanno, Alessandra Vultaggio, Mattia Giovannini, Francesca Mori
Severe reactions such as SJS, DRESS, AGEP, or TEN represent a strict indication to discontinue the drug and an absolute contraindication to its further use, regardless of the outcome of the allergy work-up [21,49]. When an immune-mediated reaction is recorded and, in particular, when an IgE-mediated mechanism is suspected, patients must undergo allergy tests [2,6]. If these tests are positive, physicians will be able to confirm the diagnosis and, whenever the drug is essential for the patient, or the possible alternative drug could lead to a loss of therapeutic efficacy, they should consider the possibility of a desensitization procedure [2,6,8,49]. In the event of a plausible clinical history but negative skin tests, a desensitization procedure or a drug provocation test may be appropriate, before considering other therapeutic alternatives. Indeed, since the sensitivity of skin tests for biologics has not been validated, in case of negative results, the choice of re-exposure to the culprit biologic drug should be based on the severity of the initial reaction. If the reaction was mild, a drug provocation test may be attempted [50]. On the contrary, desensitization is recommended when the initial reaction was moderate to severe (Figure 2) [10,20,36–43].
A qualitative approach to experiential knowledge identified in focus groups aimed at co-designing a provocation test in the study of electrohypersensitivity
Published in Annals of Medicine, 2022
Jimmy Bordarie, Maël Dieudonné, Maryse Ledent, Nicolas Prignot
The ExpoComm project had three objectives:Include EHS people in qualitative participatory research using focus groups to collect specific information related to their EMF sensitivity and what they consider necessary to include in an ideal provocation test.Co-construct this “ideal provocation test” based on this information and incorporating the necessary scientific constraints in order to propose a provocation test that meets all the criteria to be considered relevant.Implement this co-designed protocol and test its acceptability by EHS volunteers.
Diagnostic value of FeNO and MMEF for predicting cough variant asthma in chronic cough patients with or without allergic rhinitis
Published in Journal of Asthma, 2021
Li-Chang Chen, Guan-Sheng Zeng, Ling-Ling Wu, Mei Zi, Ze-Kui Fang, Hui-Zhen Fan, Hua-Peng Yu
Clinical data from 328 patients matched with the inclusion criteria were included. The bronchial provocation test was performed in 317 patients, 117 of whom were positive. Eleven subjects were tested with bronchodilation tests, and 8 of them were positive. Therefore, 125 (38.1%) subjects were diagnosed with CVA, and 203 (61.9%) patients were diagnosed with NCVA. A comparison of the clinical characteristics between the CVA and NCVA groups, including smoking history, spirometry and FeNO, is shown in Table 1. As illustrated in the table1, FeNO levels were significantly higher in patients with CVA (P < 0.001). The proportion of rhinitis subjects was 43.2% among those with CVA, which was higher than the proportion of the NCVA group (P < 0.05). In contrast, the results of spirometry (FEV1, FEV1/FVC, PEF, MMEF, MEF75, MEF50 and MEF25) were significantly lower in the CVA group than in compared with the NCVA group (P < 0.001). No significant difference was found in other parameters.