How can we better classify NSAID hypersensitivity reactions?--validation from a large database

Ibuprofen and Other Arylpropionics: The Relevance in Immediate Hypersensitivity Drug Reactions

BACKGROUND

Ibuprofen, a non-steroidal anti-inflammatory drug (NSAID), is the most frequent medication to be involved in hypersensitivity drug reactions (HDRs). Other analgesic/anti-inflammatory drugs in the arylpropionic group are also relevant, albeit to a lesser extent. Ibuprofen is widely consumed by people of all ages, both on medical prescription and over the counter; moreover, it is an organic contaminant of surface waters and foods. While numerous drugs cause HDR, ibuprofen's underlying mechanisms are more intricate and involve both specific immunological and non-immunological mediated reactions.

SUMMARY

we concentrate on immediate responses, including urticaria with or without angioedema, anaphylaxis, and angioedema, classifying reactions according to whether they are caused by single or multiple NSAIDs and based on the mechanisms at play. Both groups may experience anaphylaxis, defined as an immediate, severe systemic reaction involving at least two organs, though the frequency and severity can vary. Following this classification, more clinical manifestations can be identified. Diagnosis is partly based on a detailed clinical history, including information about ibuprofen and/or other arylpropionic derivatives involved, the interval between drug intake and symptoms onset, clinical manifestations, number of episodes, and the patient's tolerance or response to other medications - mainly non-chemically related NSAID - both before and after reactions to ibuprofen and/or other arylpropionic drugs. A drug provocation test is frequently necessary to make a diagnosis.

KEY MESSAGE

Because ibuprofen is the most widely prescribed NSAID, it is reasonable to assume its role as the leading cause of HDR will only become more important.

Analysis of Allergy and Hypersensitivity Reactions to COVID-19 Vaccines According to the EudraVigilance Database

BACKGROUND

The coronavirus disease 2019 (COVID-19) pandemic presented a new challenge in modern medicine: the development of vaccines was followed by massive population vaccinations. A few reports on post-vaccination allergic reactions have made patients and medical personnel uneasy as to COVID-19 vaccines' allergic potential. Most of the studies in this area to date have been small, and some that were based on global databases skipped most of the allergic diseases and concentrated only on anaphylaxis. We aimed to analyze the incidence of serious allergic reactions based on the EudraVigilance (EV) database, regardless of the reported symptoms and allergy mechanism.

METHODS

The total number of administrated vaccine doses was extracted on 5 October 2023 from Vaccine Tracker and included all administrations since vaccinations began in the European Economic Area (EEA). Data on serious allergic reactions to COVID-19 vaccines were extracted from the EudraVigilance database with the same time point. The code names of 147 allergic symptoms or diseases were used.

RESULTS

The frequency of serious allergic reactions per 100,000 administered vaccine doses was 1.53 for Comirnaty, 2.16 for Spikevax, 88.6 for Vaxzevria, 2.11 for Janssen, 7.9 for Novavax, 13.3 for VidPrevtyn Beta, and 3.1 for Valneva. The most prevalent reported reactions were edema (0.46) and anaphylaxis (0.40). Only 6% of these reactions were delayed hypersensitivity-oriented.

CONCLUSIONS

The overall frequency of potential serious allergic reactions to COVID-19 is very rare. Therefore, COVID-19 vaccines seem to be safe for human use. The lowest frequency of allergic reaction was observed for Comirnaty and the highest for Vaxzevria.

Evaluation of different protocols for classification of pediatric hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: Children with underlying allergic disease should be a separate subgroup

Background: Different recommendations for the classification of nonsteroidal anti-inflammatory drug hypersensitivity reactions (NSHSR) in children have been reported but a shortage still exists. Objective: The aim of the present study was to evaluate the inclusivity of two European Academy of Allergy and Clinical Immunology (EAACI) position paper classifications and to characterize the factors that underlie classification discordance in children. Methods: Patients with a history of NSHSR were evaluated with a standardized diagnostic protocol according to EAACI/ European Network for Drug Allergy (ENDA) recommendations. Children were classified and compared according to the EAACI 2013 and the pediatric EAACI/ENDA 2018 classifications. Subjects who were unclassified and those who were classified were compared. Results: Of 232 patients (median [interquartile range] age 6 years (4-11 years) with a history of NSHSR, 52 (22.4%) were confirmed with diagnostic tests. Thirty-six (69.2%) were classified as having cross-intolerance, whereas 16 patients (30.8%) were classified as selective responders. Eleven of the confirmed cases (21.2%) could not be categorized according to the 2013 EAACI classification, whereas this number was six adolescents (11.5%) when the 2018 EAACI/ENDA pediatric classification was used. Patients who were unclassified and who were all cross-intolerant were more likely to have atopic sensitization (p = 0.001) and asthma as an underlying disease (p = 0.03), higher serum eosinophil count (p = 0.022), and total immunoglobulin E levels (p = 0.007) compared with those who fit well into the classification. In multivariate regression analysis, the presence of atopic sensitization (adjusted odds ratio 20.36 [95% confidence interval, 2.14-193.48]; p = 0.009) was found to be the only significant underlying factor for an unclassified and/or blended phenotype. Conclusion: The 2013 EAACI classification resulted in a high rate of subjects who were unclassified. Despite better clinical utility, the recent pediatric EAACI/ENDA classification system still has shortcomings in terms of inclusivity for adolescents. Mostly, children with underlying allergic diseases could not be classified by the current guidelines. We propose to classify them as a separate pediatric cross-intolerance subgroup because the underlying mechanism may involve more than cyclooxygenase 1 inhibition.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs in adults: Beyond current classification

BACKGROUND

Hypersensitivity reactions (HSRs) to nonsteroidal anti-inflammatory drugs (NSAIDs) are a significant clinical issue. Several classifications have been proposed to categorize these reactions, including the current European Academy of Allergy and Clinical Immunology/European Network for Drug Allergy (EAACI/ENDA) classification. This study aimed to evaluate the applicability of this classification in a real-world clinical setting.

METHODS

We conducted a national multicenter study involving patients from nine hospitals in four major urban centers in Turkey. All patients had a suggestive clinical history of hypersensitivity reactions to NSAIDs. Researchers collected data using a structured form and classified reactions based on the EAACI/ENDA classification. Oral provocation tests with several NSAIDs were performed using a single-blind challenge per EAACI/ENDA guidelines.

RESULTS

Our retrospective study included 966 adult patients with a history of hypersensitivity to NSAIDs. The most common triggers were Acetylsalicylic Acid (ASA), paracetamol, and metamizole. The most prevalent acute NSAID hypersensitivity group was NSAID-induced urticaria/angioedema (NIUA) (34.3%). However, 17.3% of patients did not fit neatly into the current EAACI/ENDA classification. Notably, patients with underlying asthma or allergic rhinoconjunctivitis exhibited unusual reactions, such as urticaria and/or angioedema induced by multiple chemical groups of NSAIDs, blended mixed reactions, and isolated periorbital angioedema in response to multiple chemical groups of NSAIDs.

CONCLUSIONS

While the EAACI/ENDA classification system stratifies NSAID-induced hypersensitivity reactions into five distinct endotypes or phenotypes, it may not fully capture the diversity of these reactions. Our findings suggest a need for further research to refine this classification system and better accommodate patients with atypical presentations.

Lack of Major Involvement of Common CYP2C Gene Polymorphisms in the Risk of Developing Cross-Hypersensitivity to NSAIDs

Cross-hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is a relatively common, non-allergic, adverse drug event triggered by two or more chemically unrelated NSAIDs. Current evidence point to COX-1 inhibition as one of the main factors in its etiopathogenesis. Evidence also suggests that the risk is dose-dependent. Therefore it could be speculated that individuals with impaired NSAID biodisposition might be at increased risk of developing cross-hypersensitivity to NSAIDs. We analyzed common functional gene variants for CYP2C8, CYP2C9, and CYP2C19 in a large cohort composed of 499 patients with cross-hypersensitivity to NSAIDs and 624 healthy individuals who tolerated NSAIDs. Patients were analyzed as a whole group and subdivided in three groups according to the main enzymes involved in the metabolism of the culprit drugs as follows: CYP2C9, aceclofenac, indomethacin, naproxen, piroxicam, meloxicam, lornoxicam, and celecoxib; CYP2C8 plus CYP2C9, ibuprofen and diclofenac; CYP2C19 plus CYP2C9, metamizole. Genotype calls ranged from 94 to 99%. No statistically significant differences between patients and controls were identified in this study, either for allele frequencies, diplotypes, or inferred phenotypes. After patient stratification according to the enzymes involved in the metabolism of the culprit drugs, or according to the clinical presentation of the hypersensitivity reaction, we identified weak significant associations of a lower frequency (as compared to that of control subjects) of CYP2C8*3/*3 genotypes in patients receiving NSAIDs that are predominantly CYP2C9 substrates, and in patients with NSAIDs-exacerbated cutaneous disease. However, these associations lost significance after False Discovery Rate correction for multiple comparisons. Taking together these findings and the statistical power of this cohort, we conclude that there is no evidence of a major implication of the major functional CYP2C polymorphisms analyzed in this study and the risk of developing cross-hypersensitivity to NSAIDs. This argues against the hypothesis of a dose-dependent COX-1 inhibition as the main underlying mechanism for this adverse drug event and suggests that pre-emptive genotyping aiming at drug selection should have a low practical utility for cross-hypersensitivity to NSAIDs.

Food-dependent NSAID-induced hypersensitivity (FDNIH) reactions: Unraveling the clinical features and risk factors

BACKGROUND

In up to 70%-80% of patients with a suspected non-steroidal anti-inflammatory drug hypersensitivity (NSAIDH), challenge tests with the culprit drug yield negative results. On the other hand, there could be a NSAIDH overdiagnosis when anaphylaxis is the clinical manifestation. We hypothesize that some negative NSAID challenge tests and an overdiagnosis of NSAIDH occur in patients with food-dependent NSAID-induced hypersensitivity (FDNIH).

METHODS

We studied 328 patients with a suspected acute NSAIDH. FDNIH was diagnosed in patients meeting all the following: (1) tolerance to the food ingested more temporally closed before the reaction, later the episode, (2) respiratory or cutaneous symptoms or anaphylaxis related to NSAID, (3) positive skin prick test to foods and/or specific IgE to food allergens (Pru p 3, Tri a 19, Pen a 1) involved in the reaction, and (4) negative oral provocation test to the culprit NSAID.

RESULTS

199 patients (60%) were diagnosed with NSAIDH and 52 (16%) with FDNIH. Pru p 3 was involved in 44 cases (84.6%) and Tri a 19 in 6 cases (11%). FDNIH subjects were younger (p < .001), with a higher prevalence of rhinitis (p < .001) and previous food allergy (p < .001), together with a higher proportion of subjects sensitized to pollens (p < .001) and foods (p < .001). Using just four variables (Pru p 3 sensitization, Tri a 19 sensitization, anaphylaxis, and any NSAID different from pyrazolones), 95.3% of cases were correctly classified, with a sensitivity of 92% and specificity of 96%.

CONCLUSION

Evaluation of FDNIH should be included in the diagnostic workup of NSAIDH.

Drug Allergy Profile From a National Drug Allergy Registry

Background: Drug hypersensitivity reactions (DHRs) are among the most frequent reasons for consultation in allergy departments and are becoming more common due to increasing prevalence and case complexity.

Objective: To describe the most common drugs associated with clinical reactions, diagnostic methods used, and outcomes of allergic evaluations of a national drug allergy registry over a 12-year period were used.

Methods: An observational, prospective, patient’s data registry-based study was conducted to analyze all referrals to the drug allergy outpatient clinics at Al-Rashed Allergy Center, Kuwait, between 2007 and 2019. Demographics, description of DHRs, and results of allergy tests to potential causative medications were reviewed. Diagnostic methods were focused mainly on skin tests (STs) and drug provocation test (DPT), when indicated.

Results: We evaluated 1,553 patients with reported DHRs. The mean age of the population was 41.52 ± 16.93 years, and the study population consisted of 63.7% female patients. Hypersensitivity was finally confirmed in 645 (41.5%) of patients, probable in 199 (12.8%), and not confirmed/nonallergic in 709 (45.6%) patients. Anti-inflammatory drugs and analgesics contributed to 39.22% of all confirmed drug allergies, followed by antibiotics 38.1% (β-lactam antibiotics (BLs) constituted 73.98% of all antibiotics and 28.21% of all drugs), anesthetics 1.8%, and radio-contrast media 0.31%. The majority of reactions were non-immediate 51.44%. The most commonly presenting symptoms among confirmed patients were urticaria 57.80%, angioedema 42.50%, respiratory symptoms 47.60%, and erythema 33.60%. Symptoms of anaphylaxis/anaphylactic shock were reported by 284 patients (44.00%) among confirmed cases. The most common method of diagnosis was a positive clinical history (54.4% in BLs and 90.45% in nonsteroidal anti-inflammatory drugs (NSAIDs). Among confirmed allergy to BLs, a positive ST was obtained in 31.9% of patients and positive DPT in 13.7%.

Conclusion: NSAIDs and antibiotics, mainly BLs, are the most commonly implicated in confirmed allergy. In both confirmed and not confirmed/nonallergic cases, BLs are the most frequently involved DHRs which are mainly immediate, and the most commonly presenting symptoms were urticaria, angioedema, and respiratory symptoms. Diagnosis was confirmed mainly by a positive clinical history and when indicated, by positive STs or a DPT.

Characteristics and Contributing Factors Related to Nonsteroidal Anti-Inflammatory Drugs Hypersensitivity

INTRODUCTION

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) is reported to be the most common drug hypersensitivity. The aim of this study was to evaluate the characteristics of self-reported NSAID hypersensitivity and identify patients at high risk of NSAID hypersensitivity.

METHODS

Patients who presented at a single tertiary care hospital between January-December 2017 with reported NSAID hypersensitivity were evaluated. Clinical information obtained from a review of medical records was further supplemented with data gained from a telephone-administered questionnaire.

RESULTS

From a total of 535 patients with reported NSAID hypersensitivity, 301 were included in the study. The mean age of onset of NSAID hypersensitivity reaction was 30.3 ± 14.9 years old. A total of 84 patients (27.9%) were hypersensitive to 2 or more chemically unrelated NSAIDs. The leading NSAID hypersensitivity was to propionic acid derivatives (73%) followed by acetic acid derivatives (28.9%). Immediate reaction (≤1 h) was identified in 171 patients (57.8%), and angioedema was the most frequently reported symptom (179 patients, 59.5%), followed by urticaria and anaphylaxis in 85 (28.2%) and 62 (20.6%) patients, respectively. A drug provocation test was performed on 53 patients, and NSAID hypersensitivity was confirmed in 38 patients (71.6%). The independent factors identified, which could predict NSAID hypersensitivity, were personal history of allergic rhinitis/chronic rhinosinusitis (AR/CRS), onset of NSAID hypersensitivity over 15 years old, and immediate reaction.

CONCLUSION

Angioedema was the most typical symptom, and propionic acid derivatives were the most frequently reported culprit drugs. The significant risk factors predicting NSAID hypersensitivity were personal history of AR/CRS, onset of NSAID hypersensitivity reaction over 15 years old, and immediate reaction.

Evaluation of Subjects Experiencing Allergic Reactions to Non-Steroidal Anti-Inflammatory Drugs: Clinical Characteristics and Drugs Involved

Non-steroidal anti-inflammatory drugs (NSAIDs), the most commonly prescribed and consumed medicines worldwide, are the main triggers of drug hypersensitivity reactions (DHRs). The underlying mechanisms of NSAID-DHRs may be related to COX-1 inhibition (cross-hypersensitivity reactions, CRs) or to immunological recognition (selective reactions, SRs), being the latter remarkably less studied. SRs include those usually appearing within the first hour after drug intake (single-NSAID-induced urticaria/angioedema or anaphylaxis, SNIUAA), and those usually occurring more than 24 h after (single-NSAID-induced delayed reactions, SNIDR). We have evaluated the largest series of patients with SRs, analyzing the number of episodes and drugs involved, the latency for reaction onset, the clinical entities, among other variables, as well as the value of available diagnostic methods. Globally, pyrazolones and arylpropionics were the most frequent culprits (39.3% and 37.3%, respectively). Pyrazolones were the most frequent triggers in SNIUAA and arylpropionics in SNIDR. Urticaria was the most common clinical entity in SNIUAA (42.4%) followed by anaphylaxis (33.3%); whereas SNIDR induced mostly fixed drug eruption (41.1%) and maculopapular exanthema (32.6%). The percentage of patients diagnosed by clinical history was higher in SNIUAA compared with SNIDR (62.7% versus 35.3%, p = 0.00015), whereas the percentage of those diagnosed by skin tests was higher in SNIDR than in SNIUAA (47.1% versus 22.8%, p = 0.00015). Drug provocation test with the culprit was performed in 67 SNIUAA (14.5%) and in 9 SNIDR (17.6%) patients. Our results may be of interest not only for allergologists but also for other clinicians dealing with these drugs, and can be useful for the correct identification of subjects experiencing DHRs to NSAIDs, and for avoiding mislabeling. Moreover, as NSAIDs are highly consumed worldwide, our results may be of interest for evaluating other populations exposed to these drugs.

Ibuprofen-induced localized frontal and temporal forehead swellings: A rare case report

Ibuprofen, nonselective nonsteroidal anti-inflammatory drugs (NSAIDs), is one of the most commonly prescribed analgesics for managing musculoskeletal, orofacial, and postoperative pain after periodontal therapy. Although considered as one of the safest analgesic agents, the onset of adverse drug reactions after ibuprofen intake has been recently observed. The present report aims to highlight the development of localized swellings in the temporal and frontal forehead following intake of 200 mg of ibuprofen after routine oral prophylaxis. This is the first case report to document the development of an adverse drug reaction with ibuprofen in a patient following a routine dental procedure. The article also aim to comprehensively describe the most appropriate and effective method to diagnose, manage, and prevent NSAIDs-induced adverse drug reactions in routine dental practice.

Progress in understanding hypersensitivity reactions to nonsteroidal anti-inflammatory drugs

Nonsteroidal anti-inflammatory drugs (NSAIDs), the medications most commonly used for treating pain and inflammation, are the main triggers of drug hypersensitivity reactions. The latest classification of NSAIDs hypersensitivity by the European Academy of Allergy and Clinical Immunology (EAACI) differentiates between cross-hypersensitivity reactions (CRs), associated with COX-1 inhibition, and selective reactions, associated with immunological mechanisms. Three phenotypes fill into the first group: NSAIDs-exacerbated respiratory disease, NSAIDs-exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema. Two phenotypes fill into the second one: single-NSAID-induced urticaria/angioedema/anaphylaxis and single-NSAID-induced delayed reactions. Diagnosis of NSAIDs hypersensitivity is hampered by different factors, including the lack of validated in vitro biomarkers and the uselessness of skin tests. The advances achieved over recent years recommend a re-evaluation of the EAACI classification, as it does not consider other phenotypes such as blended reactions (coexistence of cutaneous and respiratory symptoms) or food-dependent NSAID-induced anaphylaxis. In addition, it does not regard the natural evolution of phenotypes and their potential interconversion, the development of tolerance over time or the role of atopy. Here, we address these topics. A state of the art on the underlying mechanisms and on the approaches for biomarkers discovery is also provided, including genetic studies and available information on transcriptomics and metabolomics.

NSAID-induced reactions: classification, prevalence, impact, and management strategies

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the leading cause of hypersensitivity drug reactions. The different chemical structures, cyclooxygenase 1 (COX-1) and/or COX-2 inhibitors, are taken at all ages and some can be easily obtained over the counter. Vasoactive inflammatory mediators like histamine and leukotriene metabolites can produce local/systemic effects. Responders can be selective (SR), IgE or T-cell mediated, or cross-intolerant (CI). Inhibition of the COX pathway is the common mechanism in CI, with the skin being the most frequent organ involved, followed by the lung and/or the nose. An important number of cases have skin and respiratory involvement, with systemic manifestations ranging from mild to severe anaphylaxis. Among SR, this is the most frequent entity, often being severe. Recent years have seen an increase in reactions involving the skin, with many cases having urticaria and/or angioedema in the absence of chronic urticaria. Aspirin, the classical drug involved, has now been replaced by other NSAIDs, with ibuprofen being the universal culprit. For CI, no in vivo/in vitro diagnostic methods exist and controlled administration is the only option unless the cases evaluated report repetitive and consistent episodes with different NSAIDs. In SR, skin testing (patch and intradermal) with 24-48 reading can be useful, mainly for delayed T-cell responses. Acetyl salicylic acid (ASA) is the test drug to establish the diagnosis and confirm/exclude CI by controlled administration. Desensitization to ASA has been extensively used in respiratory cases though it can also be applied in those cases where it is required.

Two approaches for diagnosis of nonsteroidal anti-inflammatory drug hypersensitivity in children

BACKGROUND

The oral provocation test (OPT) with culprit drug is the gold standard in the diagnosis of nonsteroidal anti-inflammatory drug hypersensitivity (NSAID-H). Some authors have proposed that the total number of OPTs required to diagnose NSAID-H is much lower with acetyl salicylic acid (ASA) provocations, regardless of patients' reaction history, and less time consuming.

OBJECTIVE

This study aims to evaluate the total number of OPTs required to confirm NSAID-H according to the drugs (ASA or culprit NSAID) used in the initial OPT.

METHODS

The study included patients with a history of NSAID-H. Data on the demographic and clinical features, coexisting chronic or allergic disease, and laboratory results were collected from medical records. The drug used for the initial OPT (ASA or culprit NSAID), results of the OPT, and the total number of OPTs were reviewed.

RESULTS

We included 56 children with suspected hypersensitivity reaction to NSAIDs. NSAID-H was confirmed in 21 children (37.5%). We calculated that if all OPTs were performed with culprit drugs as an initial choice, the number of OPTs required for diagnosis would be 3 or more in 85.7% of positive cases. The number of episodes was an independent risk factor for NSAID-H by multiple logistic regression analysis (odds ratio, 4.3; 95% confidence interval, 1.48-12.24; P = .007).

CONCLUSION

Performing an initial OPT with ASA regardless of patients' reaction history can result in much lower numbers of OPT to diagnose NSAID-H and can improve patient compliance.

NSAIDs hypersensitivity: questions not resolved

PURPOSE OF REVIEW

NSAIDs are the drugs most frequently involved in hypersensitivity reactions (HSR). These are frequently prescribed at all ages. HSR are of great concern and can affect people at any age. These drugs can induce reactions by stimulating the adaptive immune system (IgE or T cell), known as selective responders or more frequently by abnormalities in biochemical pathways related with prostaglandin metabolism. These are known as cross-intolerant. With some exceptions, skin testing and in-vitro studies are of little value in selective responders.

RECENT FINDINGS

In the last years, several classifications have been provided based on clinical symptoms, time interval between drug intake and appearance of symptoms, response to other nonchemically related NSAIDs and the underlying disease. Based on this classification, several well differentiated categories within each group of entities cross-intolerant and selective responders are now recognized. The most complex groups for evaluation are cross-intolerant in which three major groups exist: NSAIDs exacerbated respiratory disease, NSAIDs exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema in the absence of chronic spontaneous urticaria. Within the selective responders, there are two mechanisms involved: drug-specific IgE or T-cell effector responses. New entities have been added to this classification like mixed reactions within the cross-intolerant category, that must manifest as anaphylaxis and multiple immediate selective reactions.

SUMMARY

The precise evaluation of patients with NSAIDs hypersensitivity following established guidelines will improve not only our understanding but also the management of these entities. As the number of patients affected with NSAIDs is important, further studies are warranted.

[NSAID urticaria: Similar management to acute urticaria]

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most common providers of immediate hypersensitivity reactions. Among these reactions, isolated acute urticaria is the most common clinical feature with a non-allergic origin. It is a pharmacological side effect resulting from the alteration of arachidonic acid metabolism induced by NSAIDs. Diagnosis of this acute urticaria is clinical, requiring no allergy testing. Currently, the recommended therapeutic management of NSAID urticaria is the avoidance of all NSAID with COX-1 inhibitor activity (even if when reintroduced, they are most often well tolerated) and the use of selective COX-2 inhibitors. This review focuses on urticaria reactions to NSAIDs, which are simple to manage.

SIAIP position paper: provocation challenge to antibiotics and non-steroidal anti-inflammatory drugs in children

Drug hypersensitivity reactions (DHRs) in childhood are mainly caused by betalactam or non-betalactam antibiotics, and non-steroidal anti-inflammatory drugs (NSAIDs). Laboratory tests for identifying children who are allergic to drugs have low diagnostic accuracy and predictive value. The gold standard to diagnose DHR is represented by the drug provocation test (DPT), that aims of ascertaining the causative role of an allergen and evaluating the tolerance to the suspected drug. Different protocols through the administration of divided increasing doses have been postulated according to the type of drug and the onset of the reaction (immediate or non immediate reactions). DPT protocols differ in doses and time interval between doses. In this position paper, the Italian Pediatric Society for Allergy and Immunology provides a practical guide for provocation test to antibiotics and NSAIDs in children and adolescents.

NSAIDs-hypersensitivity often induces a blended reaction pattern involving multiple organs

Non-steroidal anti-inflammatory drugs (NSAIDs)-induced hypersensitivity reactions are classified by the European Network on Drug Allergy (ENDA) as either cross-reactive or selective. The former is the most frequent type and includes patients with exclusively respiratory symptoms (NSAIDs-exacerbated respiratory disease, NERD) or exclusively cutaneous symptoms: NSAIDs-induced urticaria/angioedema (NIUA); and NSAIDs-exacerbated cutaneous disease (NECD). However, although not reflected in the current classification scheme (ENDA), in clinical practice a combination of both skin and respiratory symptoms or even other organs such as gastrointestinal tract symptoms (mixed or blended reactions) is frequently observed. This entity has not been sufficiently characterised. Our aim was to clinically characterize blended reactions to NSAIDs, comparing their clinical features with NERD and NIUA. We evaluated patients with symptoms suggestive of hypersensitivity to NSAIDs who attended the Allergy Unit of the Regional University Hospital of Malaga (Malaga, Spain) between 2008 and 2015. We included 880 patients confirmed as cross-reactive based on clinical history, positive nasal provocation test with lysine acetylsalicylate (NPT-LASA), and/or positive drug provocation test (DPT) with acetylsalicylic acid (ASA), who were classified as blended (261; 29.6%), NERD (108; 12.3%) or NIUA (511; 58.1%). We compared symptoms, drugs, underlying diseases and diagnostic methods within and between groups. Among blended patients the most common sub-group comprised those developing urticaria/angioedema plus rhinitis/asthma (n = 138), who had a higher percentage of underlying rhinitis (p < 0.0001) and asthma (p < 0.0001) than NIUA patients, showing similarities to NERD. These differences were not found in the sub-group of blended patients who developed such respiratory symptoms as glottis oedema; these were more similar to NIUA. The percentage of positive NPT-LASA was similar for blended (77%) and NERD groups (78.7%). We conclude that blended reactions are hypersensitivity reactions to NSAIDs affecting at least two organs. In addition to classical skin and respiratory involvement, in our population a number of patients also develop gastrointestinal symptoms. Given the high rate of positive responses to NPT-LASA in NERD as well as blended reactions, we suggest that all patients reporting respiratory symptoms, regardless of whether they have other associated symptoms, should be initially evaluated using NPT-LASA, which poses less risk than DPT.

Registries as useful tools in characterization of allergic manifestations

PURPOSE OF REVIEW

Registries are useful to discover the applicability of data generated from randomized clinical trials (RCTs) into daily practice, and to search for real-life data usually not covered by them.

RECENT FINDINGS

In allergy, registry research brought clues to important epidemiological and clinical problems hardly accessible with other methods. The increase in the asthma prevalence in Sweden in contrast with stabilization in Denmark; the association of the prevalence of asthma and environmental factors; the knowledge of existing rhinitis international guidelines, but the poorly complacence of some of their recommendations; the low epinephrine use in anaphylaxis and the difference among European and Latin American elicitors; the predominance of β lactams or NSAIDs as drug hypersensitivity reactions inducers in different regions; the fact that most of the hereditary angioedema patients were receiving long-term prophylaxis with attenuated androgens; all the mentioned are clear examples of relevant and important data provided by current registries.

SUMMARY

Registries in allergy enlighten knowledge in areas not covered by classical investigational methods. As the number and importance of registries is growing, its contribution to the knowledge and management of allergic diseases will increase in the near future.

Polymorphism of IL10, IL4, CTLA4, and DAO Genes in Cross-Reactive Nonsteroidal Anti-inflammatory Drug Hypersensitivity

Our aim was to evaluate genetic polymorphism of molecules involved in immunoregulatory/allergic processes in patients who presented with cutaneous hypersensitivity caused by chemically unrelated nonsteroidal anti-inflammatory drugs. Polymorphisms at IL10 (-1082 G>A), IL4 (-589 C>T), CTLA4 (+49A>G), and DAO (+8956 C>G) genes were studied in 55 cases and 97 controls by the polymerase chain reaction-restriction fragment length polymorphism technique. With regard to the polymorphism at IL10 -1082, higher frequencies of the AG genotype (57% vs 39%) and G allele carriers (70% vs 48%) were found among the patients, indicating a risk effect (odds ratio [OR] = 2.56 and P = .01 for AG genotype and OR = 2.52; P = .01 for AG/GG). For the CTLA4 +49 A/G single-nucleotide polymorphism (SNP), AG genotype (31.0%) (P = .02) and G carrier (54.0%) (P = .05) frequencies were found to be significantly lower in the patient group compared with the control group (51.0% and 69.0%, respectively). The SNP DAO +8956 C>G was associated with a strong protective effect, with OR values of 0.83 for CG and 0.11 for GG genotype (P = .04 for the codominant model), suggesting an allele dose effect. The combination of IL10 and DAO SNPs in a multivariate model did not alter the OR values, suggesting independent effects for both SNPs. The results are striking. In conclusion, these results suggest that polymorphisms in regulatory targets of the immune response and in DAO gene could modulate an individual's susceptibility to nonsteroidal anti-inflammatory drug hypersensitivity reactions. Further studies will be necessary to complement our results.

Discrepancies in the diagnosis and classification of nonsteroidal anti-inflammatory drug hypersensitivity reactions in children

BACKGROUND

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently encountered in daily clinical practice. The aim of this study was to determine the confirmation rates, risk factors of NSAID hypersensitivity in children and to try to classify them with a standardized diagnostic protocol.

METHODS

All patients with a suspicion of NSAID-induced hypersensitivity were evaluated with European Network for drug Allergy (ENDA) recommendations. The children were classified as selective responders (SRs) or cross-intolerant (CI) depending on the drug provocation test (DPT) results.

RESULTS

We evaluated 106 children with a suspicion of NSAID hypersensitivity. NSAID hypersensitivity was confirmed with tests in 31 patients; 4 (12.9%) were diagnosed by skin tests and 27 (87.1%) by DPTs and two patients with a history of anaphylaxis by medical records. Eleven patients (33.3%) were classified as SRs, whereas twenty-two (66.6%) children as CIs. SRs and CIs were further classified as NSAID-induced urticaria/angioedema (n = 8), NSAID-exacerbated cutaneous disease (n = 6) and NSAID-exacerbated respiratory disease (n = 1) and single NSAID-induced urticaria/angioedema and/or anaphylaxis (n = 11). Eight (24.2%) patients could not be categorized according to ENDA/GA²LEN classification; one CI patient could not be classified based on pathomechanisms, seven CIs could not be categorized based on the underlying disease and clinical manifestations. A reaction within an hour of drug intake (aOR:3.0, 95% confidence interval: 1.18-7.67, p = 0.021), a history with multiple NSAIDs hypersensitivity (aOR:2.9, 95% confidence interval: 1.16-7.60, p = 0.022), and family history of atopy (aOR:4.0, 95% confidence interval: 1.50-10.82, p = 0.006) were found as the independent risk factors related to confirmed NSAID hypersensitivity.

CONCLUSIONS

This study suggests the presence of different phenotypes which do not fit into the current classifications in children with NSAID hypersensitivity.

Phenotypical characterization of children with hypersensitivity reactions to NSAIDs

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are the main cause of drug-induced hypersensitivity in children. Many classifications have been proposed, focusing on adults. So far, no large study has deeply investigated a pediatric cohort. The aim of the present study was to describe a population of NSAID hypersensitive patients reporting a reaction during their childhood and to verify whether it is possible to classify pediatric patients, following the EAACI/ENDA classification.

METHODS

We conducted a historical prospective study including patients evaluated from 1996 to 2015 in the allergy unit of the Montpellier University Hospital. We included 635 patients. For each patient, we recorded clinical manifestations and possible comorbidities and tried to identify possible risk factors.

RESULTS

NSAID hypersensitivity was diagnosed in 107 of 635 patients (16.9%). In this group, 43 patients (40.2%) could not be classified following the ENDA recommendations. The main discrepancies were on the patients' clinical manifestations and on their possible underlying diseases. We identified, on a multivariate analysis, some risk factors for NSAID hypersensitivity: chronic urticaria (OR 7.737, 3.375-18.296 95%CI), atopic status (OR 2.514, 1.504-4.364 95%CI), and allergic rhinoconjunctivitis (OR 1.799, 1.138-2.837 95%CI). On the basis of our results, we are proposing an adapted classification for NSAID hypersensitivity in children.

CONCLUSIONS

The current ENDA classification does not seem to be adapted for pediatric patients; a modified version does. Our study could help allergists better understand the differences between adults and children in developing hypersensitivity reactions to NSAIDs, but further large-scale prospective longitudinal analyses are required to validate this new classification.

Evaluation of hypersensitivity reactions to nonsteroidal anti-inflammatory drugs according to the latest classification

BACKGROUND/AIM

The consensus document for hypersensitivity reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) proposed by the European Network for Drug Allergy (ENDA) interest group (2011) was revised in 2013. We aimed to evaluate the usability of the latest NSAID hypersensitivity classification of ENDA.

METHOD

A total of 370 patients with a history of hypersensitivity reactions to NSAIDs among the 1250 outpatients referred for suspected drug allergy between July 2013 and June 2014 were evaluated, and 308 patients who were confirmed as having NSAID hypersensitivity were included in this study. After confirming the diagnosis, a single-blind placebo-controlled drug provocation test was performed with aspirin or diclofenac to categorize the patients according to the ENDA classification. The reactions not meeting the ENDA classification criteria were grouped as blended reactions.

RESULTS

Among the 308 patients (224 female, mean age 42.12 ± 13.24), the leading cause of hypersensitivity reactions was metamizol (30.5%) followed by aspirin (30.2%). The most common NSAID hypersensitivity subgroup was SNIUAA (46.4%) and the least common type was SNIDR (1.6%). Cross-reactivity was identified in 50.3% of the patients. In five patients (1.6%), the hypersensitivity reactions to NSAIDs did not meet the ENDA classification: Three patients experienced anaphylaxis with different NSAIDs, one patient encountered anaphylaxis with one NSAID and urticaria with other NSAIDs, and the last patient had angioedema with different NSAIDs.

CONCLUSION

The latest ENDA classification for NSAID hypersensitivity is generally a practical and useful instrument for clinicians. We only point out that anaphylaxis with different NSAIDs can be seen in a small group of patients.

Approaches to the diagnosis and management of patients with a history of nonsteroidal anti-inflammatory drug-related urticaria and angioedema

Nonsteroidal anti-inflammatory drug (NSAID)-induced urticarial and angioedema reactions are among the most commonly encountered drug hypersensitivity reactions in clinical practice. Three major clinical phenotypes of NSAID-induced acute skin reactions manifesting with angioedema, urticaria, or both have been distinguished: NSAID-exacerbated cutaneous disease, nonsteroidal anti-inflammatory drug-induced urticaria/angioedema (NIUA), and single NSAID-induced urticaria and angioedema. In some patients clinical history alone might be sufficient to establish the diagnosis of a specific type of NSAID hypersensitivity, whereas in other cases oral provocation challenges are necessary to confirm the diagnosis. Moreover, classification of the type of cutaneous reaction is critical for proper management. For example, in patients with single NSAID-induced reactions, chemically nonrelated COX-1 inhibitors can be safely used. However, there is cross-reactivity between the NSAIDs in patients with NSAID-exacerbated cutaneous disease and NIUA, and thus only use of selective COX-2 inhibitors can replace the culprit drug if the chronic treatment is necessary, although aspirin desensitization will allow for chronic treatment with NSAIDs in some patients with NIUA. In this review we present a practical clinical approach to the patient with NSAID-induced urticaria and angioedema.

Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs): classification of a Danish patient cohort according to EAACI/ENDA guidelines

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) are reported to be the second most common cause of drug hypersensitivity. In 2011, experts from the EAACI/ENDA group and GA(2)LEN proposed a new classification system for NSAID hypersensitivity. The aim of this study was to classify a patient cohort with a history of NSAID hypersensitivity according to this system.

METHODS

Patients with a clinical history of NSAID hypersensitivity referred to the Allergy Centre, Odense University Hospital between 2002 and 2011 and evaluated with oral provocation tests (OPTs) were included in the study. Medical records were retrospectively investigated with respect to the culprit NSAID(s), underlying diseases and symptoms at the primary reaction and during oral provocation tests (OPTs). Data was supplemented with a questionnaire. Classification according to EAACI guideline was based on these findings.

RESULTS

In total 149 patients were included. Of those, 39 patients (26.2%) had a positive OPT. Twenty-nine patients were classified as cross-reactive responders and 9 patients as single NSAID responders after positive OPTs with the culprit NSAID, but not to acetylsalicylic acid. All single NSAID responders reacted to non-pyrazolone drugs. Only one patient could not be classified according to the EAACI/ENDA system. An overlap between respiratory and cutaneous symptoms was found in 15/39 (38%) of patients.

CONCLUSIONS

All but one of our patients could be classified according to the EAACI classification system. Overlaps between different classes may occur much more commonly than expected.

Hypersensitivity reactions to nonsteroidal anti-inflammatory drugs: from phenotyping to genotyping

PURPOSE OF REVIEW

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequent drugs involved in hypersensitivity drugs reactions. Both immunological and nonimmunological mechanisms can be involved. We describe the different phenotypes as well as analyze the genetic basis for NSAIDs hypersensitivity.

RECENT FINDINGS

Five major clinical entities are currently accepted in the classification of hypersensitivity reactions to NSAIDs. Three are mediated by nonspecific immunological mechanisms: NSAIDs-exacerbated respiratory disease, NSAIDs-exacerbated cutaneous disease and NSAIDs-induced urticaria/angioedema. Two are mediated by specific immunological mechanisms: single-NSAID-induced urticaria/angioedema or anaphylaxis and single-NSAID-induced delayed hypersensitivity reactions. The classification becomes more complex if we consider that in an important number of cases skin and airway involvement can occur, as well as the participation of other organs.

SUMMARY

Hypersensitivity reactions to NSAIDs are more complex than for other drugs like betalactams in terms of the number and types of reactions elicited, and mechanisms involved. As NSAIDs are the most frequent cause of drug hypersensitivity, it is feasible to gather a sufficient number of cases for undertaking pharmacogenetic studies.

Anaphylaxis to diclofenac: nine cases reported to the Allergy Vigilance Network in France

Nine cases of diclofenac hypersensitivity recorded by the Allergy Vigilance Network in France from 2002 to 2012 were studied. Data from history, symptoms, skin tests, basophil activation tests, and oral challenge (OC) were recorded. Grade 3 severe anaphylactic reactions occurred in seven cases of nine. IgE-dependent anaphylaxis was confirmed in six cases: positive intradermal tests (n = 4), a syndromic reaction during skin tests (n = 1), and one case with grade 1 reaction and negative skin tests had an anaphylactic shock to the OC. A nonimmune reaction was suspected in one case. An IgE-dependent mechanism may be the predominant cause of adverse reactions to diclofenac. Allergy skin tests must be carried out sequentially at the recommended concentrations. BATs may be helpful because they can support the diagnosis of anaphylaxis. Given the risks of a direct challenge to diclofenac, OC to aspirin should be performed first to exclude a nonimmunologic hypersensitivity to NSAIDs. Tests for specific IgEs to most frequently used NSAIDs such as diclofenac and ibuprofen are urgently needed.

Multiple nonsteroidal anti-inflammatory drug-induced cutaneous disease: what differentiates patients with and without underlying chronic spontaneous urticaria?

BACKGROUND

Multiple nonsteroidal anti-inflammatory drug (NSAID) cutaneous reactors may be otherwise normal or have underlying chronic spontaneous urticaria (CSU). This study compared these two phenotypes of NSAID-hypersensitive subjects.

METHODS

A total of 97 multiple NSAID reactors underwent oral challenges with paracetamol, etoricoxib and tramadol. Atopic status was investigated in all patients, and autoreactivity was ascertained in some cases as well. Otherwise normal multiple NSAID reactors were reevaluated after 1-5 years in order to detect their proneness to CSU.

RESULTS

At the first visit, 41 patients had CSU and 56 had multiple NSAID intolerance without any underlying cutaneous disease. Altogether, 22, 10 and 6% of patients did not tolerate paracetamol, etoricoxib and tramadol, respectively, on oral challenge. Intolerance to these alternative drugs showed a strong association (p < 0.01 with all combinations). The two subgroups of patients did not show any difference in terms of mean age, gender distribution, prevalence of atopic diseases, prevalence of single offending NSAIDs and prevalence of intolerance to paracetamol, etoricoxib or tramadol on oral challenge. In all, 20% of multiple NSAID reactors without CSU at presentation developed CSU between 6 months and 5 years after the initial clinical evaluation.

CONCLUSIONS

Multiple NSAID cutaneous reactors with or without CSU seem identical from a clinical point of view, and some of the latter group show a propensity to acquire the former phenotype over time. A subset of patients apparently identical to the general population of multiple NSAID reactors also react to drugs exerting little or no cyclooxygenase-1 enzyme inhibition and might represent a distinct phenotype of NSAID-hypersensitive patients possibly characterized by a different underlying pathogenesis.

Classification and practical approach to the diagnosis and management of hypersensitivity to nonsteroidal anti-inflammatory drugs

Hypersensitivity reactions to aspirin (acetylsalicylic acid) and other nonsteroidal anti-inflammatory drugs (NSAIDs) constitute only a subset of all adverse reactions to these drugs, but due to their severity pose a significant burden to patients and are a challenge to the allergist. In susceptible individuals, NSAIDs induce a wide spectrum of hypersensitivity reactions with various timing, organ manifestations, and severity, involving either immunological (allergic) or nonimmunological mechanisms. Proper classification of reactions based on clinical manifestations and suspected mechanism is a prerequisite for the implementation of rational diagnostic procedures and adequate patient management. This document, prepared by a panel of experts from the European Academy of Allergy and Clinical Immunology Task Force on NSAIDs Hypersensitivity, aims at reviewing the current knowledge in the field and proposes uniform definitions and clinically useful classification of hypersensitivity reactions to NSAIDs. The document proposes also practical algorithms for the diagnosis of specific types of NSAIDs hypersensitivity (which include drug provocations, skin testing and in vitro testing) and provides, when data are available, evidence-based recommendations for the management of hypersensitive patients, including drug avoidance and drug desensitization.

Mediator release after nasal aspirin provocation supports different phenotypes in subjects with hypersensitivity reactions to NSAIDs

BACKGROUND

Multiple NSAID-induced urticaria/angioedema (MNSAID-UA) is an entity well differentiated from aspirin-exacerbated respiratory disease (AERD), although no detailed phenotype analysis has yet been performed. The objective was to evaluate the functional characteristics of MNSAID-UA subjects by analyzing the response to nasal lysine-aspirin challenge and measurement of nasal inflammatory mediator release compared with AERD subjects and controls.

METHODS

The study included 85 subjects with confirmed hypersensitivity to NSAIDs (≥3 episodes with >2 different NSAIDs or positive drug provocation) with either cutaneous (MNSAID-UA, n = 25) or respiratory manifestations (AERD, n = 60) and 30 tolerant controls (15 aspirin-tolerant asthmatic patients and 15 healthy controls). Nasal lavages at 0, 15, 60, and 120 min after lysine-aspirin challenge were analyzed for ECP, tryptase, PGE2 , PGD2 , LTD4 , and LTE4 .

RESULTS

Lysine nasal challenge was positive in 80% of the AERD cases but positive only in 12% of the MNSAID-UA group. MNSAID-UA subjects showed no changes in nasal ECP, whereas subjects with AERD had increased levels of ECP, with the highest peak at 15 min after challenge (P < 0.05). Tryptase levels were higher in AERD compared with MNSAID-UA and controls with the highest release of tryptase at 60 min (P < 0.05). Significant increases in PGD2 , LTD4 , and LTE4 were observed in AERD (at 60 min for PGD2 , LTD4 , and LTE4 ) but not in MNSAID-UA or control subjects (P < 0.05).

CONCLUSIONS

Data support the observation that MNSAID-UA, although sharing a common response with AERD to COX inhibitors, seems to have a distinctive phenotype, based on the response to nasal challenge and the release of inflammatory mediators.

Severe drug-induced anaphylaxis: analysis of 333 cases recorded by the Allergy Vigilance Network from 2002 to 2010

BACKGROUND

A few series of well-documented cases of severe drug-induced anaphylaxis (SDA) are available.

METHODS

Cases collected by the Allergy Vigilance Network from 2002 to 2010 were analyzed for clinical signs, causative drugs, and efficacy of a stepwise approach to diagnosis, using skin tests, laboratory tests, and oral challenges.

RESULTS

Three hundred and thirty-three cases concerned 300 adults (90.1%) and 33 children (9.9%): 206 females (61.9%) and 127 males (38.1%). Mean age was 42.7 ± 18 years. Anaphylactic shock (76.6%), severe systemic reactions (10.5%), acute laryngeal edema (9%), severe bronchospasm (2.1%), and six fatal cases (1.8%) were recorded. There were 270 cases (81.1%) of ambulatory anaphylaxis. Sixty-three cases (18.9%) occurred during anesthesia. Hospitalization was required in 94.8% of cases. 23.7% of patients were admitted to an intensive care unit. Epinephrine was used in 57.9% of cases. Eighty-four drugs were incriminated: antibiotics (49.6%), muscle relaxants, latex and anesthetics (15%), nonsteroidal anti-inflammatory drugs (10.2%), acetaminophen (3.9%), iodinated or magnetic resonance imaging contrast media (4.2%), immunotherapy and vaccines (3.9%), and other drugs (13%). Among antibiotics, amoxicillin (97 cases), other penicillins (four cases), cephalosporins (41 cases), quinolones (15 cases), and pristinamycin (seven cases) were the most common. The diagnosis of drug hypersensitivity was obtained by skin tests in 72.9%, laboratory tests only in 2.4% of cases, and oral challenges (OCs) only in 3.9% of cases.

CONCLUSIONS

Three hundred and thirty-three case reports provided data on drugs involved in severe anaphylaxis. The efficacy of skin tests and poor use of laboratory tests are underlined. Further progress may depend on OCs.

Lornoxicam : pharmacology and usefulness to treat acute postoperative and musculoskeletal pain a narrative review

INTRODUCTION

Non-steroidal anti-inflammatory drugs (NSAIDS) are commonly used for acute pain management. Lornoxicam is a nonselective NSAID for oral and intravenous administration. It has been available for human use since two decades and there is a growing body of evidence supporting its efficacy and tolerability for management of acute pain.

AREAS COVERED

Public domain literature around the clinical use of lornoxicam for acute pain management has been reviewed.

EXPERT OPINION

There are a growing number of clinical studies documenting lornoxicam effects for short-term treatment of acute postoperative pain following various surgical procedures. It has in the majority of comparative studies been shown superior as compared to paracetamol, non-inferior compared to other NSAIDs, and commonly similarly effective as standard clinical doses of opioids, but associated with better tolerability. Its effect on other acute pain, for example, headache, back pain, or sports injury is not well studied. Lornoxicam 8 mg twice daily is a seemingly effective and tolerable alternative NSAID for use as sole agent or as part of multimodal analgesia in adults. Available data does however not show any outstanding benefits or special risk. The general precautions with regard to the use of NSAIDs, the potential risks, for example, gastrointestinal bleeding and or cardiovascular side effects must be acknowledged.

Non-steroidal anti-inflammatory drug hypersensitivity in adults and the factors associated with asthma

BACKGROUND

Characteristics of non-steroidal anti-inflammatory drug (NSAID)-hypersensitivity (NH) associated with underlying/accompanying diseases has not been studied in Turkey. In addition, the factors associated with asthma in NH patients are not well known. The present study aimed to investigate the relationship between NH and chronic urticaria, rhinitis/rhinosinusitis, and asthma in an effort to identify NH phenotypes. The study's secondary aim was to identify the factors associated with asthma in NH patients and the NSAID reaction pattern in asthmatics.

METHODS

Data for 1137 NH patients in our hospital's allergy clinic database were retrospectively analyzed. Patients were divided into 5 groups based on their accompanying diseases (chronic urticaria, asthma, rhinitis/rhinosinusitis). Asthmatic patients were compared to non-asthmatic patients to identify the factors associated with asthma.

RESULTS

Reaction patterns and patient characteristics in each group differed from those in the reference group (NH only group). Asthma in patients with NH was associated with female gender, sinonasal polyposis/polyp surgery, rhinitis/rhinosinusitis, NSAID-induced rhinitis/asthma or a blended reaction pattern, immediate reaction following NSAID intake, self-reported history of food allergy, and family history of asthma; the odds ratios and 95% CIs were 1.35 (1.02-1.78), 13.52 (8.74-20.9)/10.94 (6.73-17.77), 12.06 (9-16.17), 15.28 (10.45-22.36)/2.43 (1.70-3.45), 1.76 (1.31-2.35), 1.49 (1.04-2.14), and 3.1 (2.35-4.08), respectively. The characteristics of the asthmatic patients that had urticaria/angioedema-type reactions to NSAID intake (pseudo Samter's syndrome) differed from those in the asthmatics with rhinitis/asthma-type reactions.

CONCLUSIONS

Chronic urticaria, rhinitis, and asthma commonly accompany NH. NSAID response patterns in NH patients may help differentiate groups of patients. The present study identified factors associated with asthma in NH patients and observed that there seems to be different phenotypes of Samter's syndrome, for which a new classification scheme was proposed.

Drug provocation tests: up-date and novel approaches

Summary

Drug provocation tests (DPTs) are often needed when evaluating patients with suspected drug hypersensitivity reactions. General considerations on DPTs, with regard to indications, contraindications, methods, limitations and interpretations have been thoroughly addressed and various protocols are published. However, the field of drug allergy is changing and DPTs make no exception. Novel (or sometimes, simply renewed) approaches arise, awaiting to be either validated or refuted in larger studies in the future. Instead of covering the whole topic of DPTs, this paper will address these recent and challenging aspects.

Drug provocation tests in the diagnosis of hypersensitivity reactions to non-steroidal anti-inflammatory drugs in children

INTRODUCTION

Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) are the most frequently reported reaction to drugs. They can be induced by pharmacological mechanisms (cyclooxygenase inhibition), with patients classified as cross-intolerant (CI), or by specific immunological mechanisms, IgE or T cell, with patients classified as selective reactors (SR).

OBJECTIVE

To analyse a large group of children with a history of NSAID hypersensitivity diagnosed by drug provocation test (DPT).

METHODS

A group of 63 children with a history of NSAID hypersensitivity were evaluated by DPT. The children were classified as CI or SR depending on the acetyl salicylic acid (ASA) response in DPT. The atopic status was also assessed by prick tests and total IgE in serum.

RESULTS

Using DPT, 68.2% were confirmed as having hypersensitivity, 58.1% classified as CI and 41.9% as SR. Of the 119 DPT performed, 73 were positive (53.4% to ibuprofen, 37% to ASA, 8.2% to metamizol and 14% to paracetamol); angio-oedema was present in 86.3% of cases. All CI cases tolerated the administration of paracetamol. A significant number of the CI children were atopic compared with the SR children and non-allergic controls.

CONCLUSION

In these children, CI hypersensitivity to NSAIDs was the most frequent type of hypersensitivity reaction. Ibuprofen was the drug most often involved, angio-oedema the most common entity, and frequently associated with atopy. DPT proved a safe approach for diagnosing these patients.

Anaphylaxis to ibuprofen in a 12-year-old boy

Non-steroidal anti-inflammatory (NSAIDs) drugs are a group of medications acting through cyclooxygenase  (COX-1) and cyclooxygenase  (COX-2) enzymes inhibition. Hypersensitivity reactions to NSAIDs, although not rare, are poorly characterised and often go undiagnosed especially in children. We present in this paper a case of ibuprofen anaphylaxis that exemplifies the challenges involved in diagnosis and management of hypersensitivity reactions to NSAIDs.