Value of the clinical history in the diagnosis of urticaria/angioedema induced by NSAIDs with cross-intolerance

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.

An Update on Nonsteroidal Anti-Inflammatory Drug-Induced Urticaria

BACKGROUND

Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (HR-NSAIDs) are common adverse events related to the widespread use of over-the-counter NSAIDs for the treatment of a variety of inflammatory conditions. Urticaria is the most commonly reported immediate cutaneous clinical sign of HR-NSAIDs, but it can be a manifestation of pathophysiologically different clinical entities that require different therapeutic strategies. The aim of this study is to ease the identification of the correct phenotype of HR-NSAIDs in patients reporting urticaria associated with the intake of NSAIDs and provide updated information about their diagnosis and management.

METHODS

The study is a narrative review conducted by collecting the most relevant and up-todate data related to the classification, pathophysiology, severity, and prognosis of NSAID hypersensitivity reactions. PubMed and Embase scientific databases were used as search engines to select relevant articles.

RESULTS

Patients developing HR-NSAIDs can be divided into two categories: selective responders (SR), who develop reactions after the administration of a single specific NSAID due to an underlying IgE or T-cell mediated hypersensitivity mechanism, or cross-intolerant (CI), who develop reactions to more than one chemically unrelated NSAIDs due to abnormalities in the biochemical pathways related with prostaglandin metabolism, independently from an underlying immunological mechanism. Five major different categories of HR-NSAIDs have been identified: NSAIDs-exacerbated cutaneous disease (NECD), NSAIDs-induced urticaria/angioedema with/without respiratory and systemic symptoms of anaphylaxis (NIUAA), and NSAIDsexacerbated respiratory disease (NERD), which are developed by CI patients, and single NSAIDs-induced urticaria, angioedema and/ or anaphylaxis (SNIUAA) and single NSAIDsinduced delayed hypersensitivity reactions (SNIDHR), which are developed by CI patients. In vivo and in vitro diagnostic tests have rarely been shown to be reliable in all these entities and therefore are not routinely used in clinical practice. The management in SR patients consists of strict avoidance of the culprit drug, while for cross-intolerance reactions oral tolerance tests with safe alternative drugs (e.g. weak COX-1 inhibitors or selective COX-2 inhibitors) can be performed.

CONCLUSION

HR-NSAIDs are being observed with increasing frequency, however, the pathogenesis behind some NSAIDS-associated clinical entities is still unclear. Diagnosis is mostly based on a thorough clinical history and confirmed by a drug challenge test. Clinical management is based on strict avoidance and use of alternative tolerated medications. Overall, all therapeutic decisions depend on the correct identification of the type of reaction the patient experienced.

Managing Chronic Urticaria and Recurrent Angioedema Differently with Advancing Age

Angioedema and urticaria affect people of all ages. Accurate diagnosis and optimum management is essential for healthy aging. Older people continue to experience mast cell-mediated urticaria and angioedema, with a higher prevalence of autoimmune and a lower prevalence of autoallergic disease. Bradykinin-mediated angioedemas are more common in the elderly because of their association with angiotensin-converting enzyme inhibitor (ACEI) treatment. Acquired C1-inhibitor deficiency, another bradykinin-mediated angioedema, occurs predominantly in older people, whereas hereditary angioedema due to C1-inhibitor deficiency continues to cause symptoms, even in old age. Drug-induced angioedemas disproportionately affect older people, the most frequent users of ACEIs, aspirin, and nonsteroidal anti-inflammatory drugs. Accurate diagnosis and targeted treatment prevent unnecessary morbidity and mortality. Second-generation antihistamines with omalizumab if required are effective and well tolerated in older people with mast cell-mediated urticaria. For bradykinin-mediated angioedemas, these drugs are ineffective. C1-inhibitor replacement or blockade of kallikrein or the bradykinin B2 receptor of the contact pathway is required to treat hereditary angioedema and may be considered in other bradykinin-mediated angioedemas, if supportive treatment is insufficient. For aspirin-related angioedema and urticaria, alternative medications or, exceptionally, desensitization may be required.

Hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) - a retrospective study

BACKGROUND

The aim of this study was to verify the validity of clinical history and oral provocation challenges of patients with NSAID hypersensitivity and to identify safe alternatives. The COX-2 inhibitor etoricoxib, in particular, was studied.

PATIENTS AND METHODS

In all, 104 patients with confirmed diagnoses of NSAID hypersensitivity treated at the Department of Dermatology, Frankfurt University Hospital, Germany between 2004 and 2012 were retrospectively studied.

RESULTS

The medical history and hypersensitivity symptoms during oral provocation testing (OPT) largely coincided and were mostly mild to moderate. Acetylsalicylic acid (ASA) was the most frequent trigger both anamnestically (27.9 %) and during OPT (47.8 %). Etoricoxib caused the fewest reactions during OPT (4.2 %). Acetaminophen led to reactions in only 6.7 % of the cases studied although it was named more often in clinical histories (14 %).

CONCLUSIONS

OPT should be the aim whenever possible as most symptoms are mild to moderate. To distinguish between selective and cross-hypersensitivity reactions, ASA should be part of the test protocol. Furthermore, the findings of this study indicate that etoricoxib and acetaminophen are safe treatment alternatives in case of NSAID hypersensitivity. However, these drugs should not be administered without prior OPT in an inpatient setting, as severe symptoms can occur.

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.

Tolerability to paracetamol and preferential COX-2 inhibitors in patients with cross-reactive nonsteroidal anti-inflammatory drugs hypersensitivity

Background

Acetylsalicylic acid/aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used drugs that may cause hypersensitivity reactions in a substantial proportion of patients. Physicians ought to be aware of these situations.

Objective

We aimed to present the clinical characteristics and rates of tolerability to cyclooxygenase (COX)-2 inhibitor analgesics in patients who had admitted due to multiple cross-reactive type of NSAID hypersensitivity.

Methods

The files of the patients who had admitted with multiple NSAIDs-induced symptoms were investigated retrospectively. Age, sex, underlying diseases, clinical manifestation, skin test results, and drug provocation test results were analyzed.

Results

In 105 patients with multiple cross-reactive type of NSAID hypersensitivity, we found the rate of cross-reactivity to any of the relatively safe alternatives including paracetamol, meloxicam, and nimesulide to be 16.1%. The rate of cross-reactivity to these relatively safe drugs was significantly higher in patients with a history of anaphylaxis induced by NSAID intake (p = 0.006).

Conclusion

The diagnosis of COX-1-mediated multiple NSAID hypersensitivity can be often established with a detailed history. Although rare, severe hypersensitivity reactions may be observed in these patients. Undesired situations for both patients and physicians may be avoided by testing relatively safe paracetamol and COX-2 inhibitors in experienced centers.

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.

Update on the Management of Nonsteroidal Anti-Inflammatory Drug Hypersensitivity

The clinical phenotypes of nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity are heterogeneous with various presentations including time of symptom onset, organ involvements, and underlying pathophysiology. Having a correct diagnosis can be challenging. Understanding their respective mechanisms as well as developing a comprehensive classification and diagnostic algorithm are pivotal for appropriate management strategy. Treatment modalities are based on the subtypes and severity of hypersensitivity reactions. Insights into the phenotypes and endotypes of hypersensitivity reactions enable personalized management in patients with suboptimal control of disease. This review updated the recent evidence of pathophysiology, classification, diagnostic algorithm, and management of NSAID hypersensitivity reactions.

A Multicenter Retrospective Study on Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in Children: A Report from the European Network on Drug Allergy (ENDA) Group

BACKGROUND

Diagnosis of hypersensitivity (HS) reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) in children is complex. The real prevalence of NSAID HS remains unknown because a drug provocation test (DPT) is not always performed with the culprit NSAID.

OBJECTIVE

To describe and compare the diagnostic workup among different European centers and to find out the real proportion of NSAID HS by performing a DPT with the culprit drug.

METHODS

We retrospectively collected data from children (0-10 years) and adolescents (10-18 years) with a history of NSAID reactions and who underwent a complete allergy workup including DPTs with the culprit in 6 different pediatric centers: Belgrade, Florence, Geneva, Madrid, Porto, and Rome.

RESULTS

A total of 693 children with a history of NSAID reactions were enrolled, and a total of 526 DPTs were performed with the culprit NSAID. The diagnosis of NSAID HS was confirmed in 19.6% (103 of 526) of children by performing a DPT with the culprit drug. The major differences in the allergy workup among the 6 centers concerned the duration of the DPT and the practical use of skin tests for diagnosing NSAID HS. In addition, the use of acetyl salicylic acid to differentiate single reactor or cross-intolerance patients is not common, except in Spain.

CONCLUSION

The value of this study is that although different approaches are used around Europe to diagnose NSAID HS, we found that the percentage of confirmed NSAID HS is less than 20%. This highlights the importance of the DPT in confirming or excluding NSAID HS in the pediatric population.

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.

Cyclo-oxygenase selectivity and chemical groups of nonsteroidal anti-inflammatory drugs and the frequency of reporting hypersensitivity reactions: a case/noncase study in VigiBase

To date, no reports of hypersensitivity reactions (HSRs) among nonsteroidal anti-inflammatory drugs (NSAIDs) according to cyclo-oxygenase (COX) selectivity and chemical groups have been published in a single study. The present study assessed the reporting frequency of HSRs for NSAIDs based on their relative inhibitory potency toward COX enzymes and chemical groups, including the presence/absence of a functional sulfonamide group, in strata observed 5 years after market authorization. A case/noncase study was performed among individual case safety reports (ICSRs) with NSAIDs as suspected drugs in VigiBase, the WHO spontaneous reporting database. Cases were ICSRs mentioning angioedema and anaphylactic/anaphylactoid shock conditions, while noncases were ICSRs without HSRs. NSAIDs were categorized into (i) NSAIDs with high COX-2 selectivity (coxibs), (ii) noncoxib NSAIDs with COX-2 preference, (iii) NSAIDs with poor selectivity, or (iv) NSAIDs with unknown selectivity. Chemical groups were defined based on the Anatomical Therapeutic Chemical classification system and the presence/absence of a functional sulfonamide group. Reporting odds ratios (RORs) and 95% confidence intervals (95% CIs) were calculated using logistic regression analysis. We identified 13 229 cases and 106 444 noncases. In the first 5 years after marketing, poor-selectivity NSAIDs and acetic acid derivatives were associated with the highest ROR of HSRs (age- and sex-adjusted ROR 2.12, 95% CI 1.98-2.28; and ROR 2.21, 95% CI 1.83-2.66, respectively) compared with coxibs, and sulfonamide NSAIDs were associated with the highest ROR of HSRs compared with nonsulfonamide NSAIDs (age- and sex-adjusted ROR 1.38, 95% CI 1.29-1.47). After the first 5 years of marketing, most of the RORs returned to approximately 1.

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.

Characterization of Patients with Ibuprofen Hypersensitivity

BACKGROUND

Ibuprofen is the most frequently used over-the-counter nonsteroidal anti-inflammatory drug (NSAID) in North America. While it has been commonly implicated in drug-induced hypersensitivity reactions, there is limited literature specifically on ibuprofen hypersensitivity.

OBJECTIVES

To characterize the demographics and clinical course of hypersensitivity reactions in a cohort of patients with ibuprofen allergy.

METHODS

A retrospective chart review of patients diagnosed with ibuprofen allergy was conducted between 2008 and 2016 in an allergy clinic at a tertiary care academic institution. Demographics and clinical information were obtained, and severity of reactions was assessed by a standardized grading system.

RESULTS

A total of 41 patients were included of whom 27 were female. The mean age at first reaction to ibuprofen was 33 ± 13.9 years. The medi an time from the first reaction to the time of diagnosis was 1 year (0-3). The median time from ibuprofen exposure to the onset of symptoms was 30 min (16-101). The median duration of symptoms was 180 min (60-1,440). Urticaria and angioedema were seen in 90% of patients. The reactions were either mild (46%) or moderate (51%) in severity, but 1 patient had severe anaphylaxis. Cross-reactivity to other NSAIDs or acetaminophen was seen and presented with mostly mild reactions.

CONCLUSION

In our cohort of patients, ibuprofen hypersensitivity affected females more commonly than males, and presented with mainly cutaneous manifestations. Onset of symptoms was rapid (< 60 min). Reactions typically ranged in severity from mild to moderate although there was a risk of severe anaphylaxis. There was potential cross-reactivity with other NSAIDs or acetaminophen. The results of our study contribute to the understanding of the demographics and clinical course of ibuprofen hypersensitivity reactions.

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.

An Overview of Nonsteroidal Antiinflammatory Drug Reactions

Nonsteroidal antiinflammatory drugs (NSAIDs), including aspirin, are among the most commonly used drugs worldwide. They account for a large number of adverse drug reactions (ADRs). The prevalence of NSAID-induced reactions is increasing. Distinguishing between a predicted side effect of a drug and a potentially life-threatening hypersensitivity reaction is essential to manage the affected patient. However, most clinicians find it difficult to diagnose these types of reactions despite published classification schemes. In this overview, we provide an in-depth review of NSAID classification, types of NSAID reactions, diagnostic tactics, and management strategies to provide the reader with a greater understanding of NSAID-induced reactions.

Practical approach to the treatment of NSAID hypersensitivity

INTRODUCTION

Non-steroidal anti-inflammatory drugs (NSAIDs) are the most frequently involved in drug hypersensitivity reactions (DHR). NSAIDs are prescribed for different processes and some NSAIDs can be obtained over the counter. Areas covered: We analyse the practical approaches for managing and treating NSAID-DHR considering the five major groups of entities recognised, divided into two categories: those responding to strong COX-1 inhibitors and possibly weak COX-1 or selective COX-2 inhibitors named cross-intolerant (CI), and those induced by a single drug or drug group with good tolerance to strong COX-1 inhibitors, known as allergic reactions (SR). An analysis of the recent literature indicates that two approaches can be followed for CI: to give acetyl salicylic acid to confirm NSAID hypersensitivity or to give alternative drugs to provide a solution for the treatment of pain, fever, inflammation or other conditions. Desensitisation approaches have been undertaken, but mainly for CI cases with respiratory airway involvement and they are very rarely used for CI with cutaneous involvement or SR. Expert commentary: DHR to NSAIDs are now recognised as one of the most important problems in the evaluation and management of drug allergy. Because no diagnostic tests exist, important resources are needed to evaluate these patients.

Natural evolution in patients with nonsteroidal anti-inflammatory drug-induced urticaria/angioedema

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most frequent triggers of drug hypersensitivity with NSAIDs-induced urticaria/angioedema (NIUA) the most common phenotype. Loss of hypersensitivity has been reported for IgE-mediated reactions; however, it has not been assessed in nonimmunological reactions such as NIUA. We evaluated NSAID-hypersensitivity over time in NIUA patients.

METHODS

Patients confirmed as NIUA by positive drug provocation test (DPT) with acetylsalicylic acid (ASA) during 2005-2012 (V1) were included (n=38). Subjects were prospectively re-evaluated by DPT with ASA/other NSAIDs at two time points between 2013 and 2015 (V2 and V3). Atopy was assessed by skin prick test (SPT) using inhalant and food allergens.

RESULTS

Patients were evaluated at V1 and re-evaluated after 60 months (V2; IR:48-81) and a further 18 months (V3; IR:14-24). At V2, the majority (24; 63.15%) tolerated ASA and other NSAIDs (Group A) while 14 (36.84%) still reacted (Group B). At V3, all Group A patients remained tolerant; all Group B patients remained hypersensitive. The number of previous episodes reported at V1 and the percentage of reactions induced by ASA/ibuprofen were significantly lower in Group A (P=.005 and P=.006, respectively). Group A patients developed tolerance 72 months (IR:45-87) after their last evaluated reaction (V1); this interval was shorter in nonatopics (P=.003), patients who experienced reactions over 1 hour after NSAIDs administration (P=.001), and those who experienced isolated urticaria after NSAID intake (P=.024).

CONCLUSIONS

NIUA patients may develop tolerance to NSAIDs over time, a process that seems to be influenced by atopy and type of clinical reaction.

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.

Copy number variation in ALOX5 and PTGER1 is associated with NSAIDs-induced urticaria and/or angioedema

OBJECTIVE

Cross-intolerance to NSAIDs is a class of drug hypersensitivity reaction, of which NSAIDs-induced urticaria and/or angioedema (NIUA) are the most frequent clinical entities. They are considered to involve dysregulation of the arachidonic acid pathway; however, this mechanism has not been confirmed for NIUA. In this work, we assessed copy number variations (CNVs) in eight of the main genes involved in the arachidonic acid pathway and their possible genetic association with NIUA.

MATERIALS AND METHODS

CNVs in ALOX5, LTC4S, PTGS1, PTGS2, PTGER1, PTGER2, PTGER3, and PTGER4 were analyzed using TaqMan copy number assays. Genotyping was carried out by real-time quantitative PCR. Individual genotypes were assigned using the CopyCaller Software. Statistical analysis was carried out using GraphPad prism 5, PLINK, EPIDAT, and R version 3.1.2.

RESULTS AND CONCLUSION

A total of 151 cases and 139 controls were analyzed during the discovery phase and 148 cases and 140 controls were used for replication. CNVs in open reading frames were found for ALOX5, PTGER1, PTGER3, and PTGER4. Statistically significant differences in the CNV frequency between NIUA and controls were found for ALOX5 (Pc=0.017) and PTGER1 (Pc=1.22E-04). This study represents the first analysis showing an association between CNVs in exonic regions of ALOX5 and PTGER1 and NIUA. This suggests a role of CNVs in this pathology that should be explored further.

Clinical approach on challenge and desensitization procedures with aspirin in patients with ischemic heart disease and nonsteroidal anti-inflammatory drug hypersensitivity

BACKGROUND

Hypersensitivity to acetylsalicylic acid (ASA) constitutes a serious problem for subjects with coronary artery disease. In such subjects, physicians have to choose the more appropriate procedure between challenge and desensitization. As the literature on this issue is sparse, this study aimed to establish in these subjects clinical criteria for eligibility for an ASA challenge and/or desensitization.

METHODS

Collection and analysis of data on ASA challenges and desensitizations from 10 allergy centers, as well as consensus among the related physicians and an expert panel.

RESULTS

Altogether, 310 subjects were assessed; 217 had histories of urticaria/angioedema, 50 of anaphylaxis, 26 of nonimmediate cutaneous eruptions, and 17 of bronchospasm related to ASA/nonsteroidal anti-inflammatory drugs (NSAID) intake. Specifically, 119 subjects had index reactions to ASA doses lower than 300 mg. Of the 310 subjects, 138 had an acute coronary syndrome (ACS), 101 of whom underwent desensitizations, whereas 172 suffered from a chronic ischemic heart disease (CIHD), 126 of whom underwent challenges. Overall, 163 subjects underwent challenges and 147 subjects underwent desensitizations; 86 of the latter had index reactions to ASA doses of 300 mg or less. Ten subjects reacted to challenges, seven at doses up to 500 mg, three at a cumulative dose of 110 mg. The desensitization failure rate was 1.4%.

CONCLUSIONS

In patients with stable CIHD and histories of nonsevere hypersensitivity reactions to ASA/NSAIDs, an ASA challenge is advisable. Patients with an ACS and histories of hypersensitivity reactions to ASA, especially following doses lower than 100 mg, should directly undergo desensitization.

Non-steroidal anti-inflammatory drug hypersensitivity in children

INTRODUCTION

There are rather few publications about hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAID) in the paediatric age. In this study, we aimed to assess the frequency of confirmed NSAID hypersensitivity in children with a previous reported reaction to NSAID in order to investigate the role of the drug provocation test (DPT) in the diagnostic workup and to explore the factors associated with confirmed NSAID hypersensitivity.

METHODS

We conducted a retrospective analysis of the clinical files from every patient under 18 years old who attended two Portuguese paediatric allergy outpatient clinics, from January 2009 to August 2014, due to a suspected NSAID hypersensitivity.

RESULTS

We included 119 patients, with a median age of nine years (P₂₅-P₇₅: 5-14). Ibuprofen was the commonest implicated NSAID in the patients' reports (n=94-79%). After DPT, NSAID hypersensitivity was confirmed in nine (7.6%) patients, excluded in 93 (78.2%) and was inconclusive in 17 (14.3%). In the majority (n=95-79.8%), the reaction occurred in the first 24h after intake. Eighty-four patients (70.6%) reported only cutaneous manifestations and 18 (15.1%) had systemic symptoms. Anaphylaxis represented a relative risk to NSAID hypersensitivity confirmation. No association was found for atopy and the number of previous reactions.

CONCLUSION

In our study, NSAID hypersensitivity was confirmed in a small proportion of the patients with a previous reported reaction. Ibuprofen was the most implicated drug with urticaria/angio-oedema as the commonest manifestation. Anaphylaxis was associated with confirmed drug hypersensitivity. The drug provocation test was essential to establish the diagnosis.

Respiratory hypersensitivity reactions to NSAIDs in Europe: the global allergy and asthma network (GA2 LEN) survey

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most prevalent drugs inducing hypersensitivity reactions. The aim of this analysis was to estimate the prevalence of NSAID-induced respiratory symptoms in population across Europe and to assess its association with upper and lower respiratory tract disorders.

METHODS

The GA² LEN survey was conducted in 22 centers in 15 European countries. Each of 19 centers selected random samples of 5000 adults aged 15-74 from their general population, and in three centers (Athens, Munich, Oslo), a younger population was sampled. Questionnaires including questions about age, gender, presence of symptoms of asthma, allergic rhinitis, chronic rhinosinusitis, smoking status, and history of NSAID-induced hypersensitivity reactions were sent to participants by mail. Totally, 62 737 participants completed the questionnaires.

RESULTS

The mean prevalence of NSAID-induced dyspnea was 1.9% and was highest in the three Polish centers [Katowice (4.9%), Krakow (4.8%), and Lodz (4.4%)] and lowest in Skopje, (0.9%), Amsterdam (1.1%), and Umea (1.2%). In multivariate analysis, the prevalence of respiratory reactions to NSAIDs was higher in participants with chronic rhinosinusitis symptoms (Odds Ratio 2.12; 95%CI 1.78-2.74), asthma symptoms in last 12 months (2.7; 2.18-3.35), hospitalization due to asthma (1.53; 1.22-1.99), and adults vs children (1.53; 1.24-1.89), but was not associated with allergic rhinitis.

CONCLUSION

Our study documented significant variation between European countries in the prevalence of NSAID-induced respiratory hypersensitivity reactions, and association with chronic airway diseases, but also with environmental factors.

Genetic determinants of metamizole metabolism modify the risk of developing anaphylaxis

Metamizole is a NSAID that has been banned in several countries because of its toxicity. It is often involved in selective hypersensitivity reactions and most hypersensitivity patients develop anaphylaxis. Metamizole is rapidly metabolized, and metabolic profiles are related to genetic factors. We analyzed whether genetic determinants of metamizole metabolism influence the risk of developing hypersensitivity in 265 patients diagnosed with hypersensitivity to metamizole and 362 healthy individuals who tolerated metamizole. Slow acetylation is associated with an increased risk of developing selective hypersensitivity to metamizole [odds ratio for slow alleles=2.17 (95% confidence interval=1.44-3.27); P=0.00016], and particularly anaphylaxis [odds ratio=4.77 (95% confidence interval=2.28-9.98); P=0.000006], with a significant gene-dose effect. The association was not identified in patients with cross-hypersensitivity. Cytochrome P450 2C9 (CYP2C9) and cytochrome P450 2C19 (CYP2C19) genotypes did not influence risk association. Our findings raise the hypothesis of genetically determined metabolic variability as a risk factor for developing anaphylaxis with metamizole.

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.

Developments in the field of allergy in 2013 through the eyes of Clinical and Experimental Allergy

2013 was another exciting year for allergy in general and Clinical and Experimental Allergy in particular. In the field of asthma and rhinitis, there continued to be a focus on heterogeneity and phenotypes with increasing use of biostatistical techniques to determine clusters of similar populations. Obesity- and aspirin-associated disease are intriguing associations with asthma which were explored in a number of papers. We published a number of excellent papers on mechanisms of airway inflammation and how this relates to physiology, pathology, genetics and biomarkers in both human and experimental model systems. In terms of mechanisms, there is less on individual cell types in allergic disease at the moment, but the immunology of allergic disease continued to fascinate our authors. Another area that was popular both in the mechanisms and in the epidemiology sections was early life events and how these lead to allergic disease, with an increasing focus on the role of the microbiome and how this influences immune tolerance. In the clinical allergy section, oral immunotherapy for food allergy is clearly a major topic of interest at the moment as was in vitro testing to distinguish between sensitization and allergic disease. There was less on inhalant allergy this year, but a good representation from the drug allergy community including some interesting work on non-IgE-mediated mechanisms. In the allergen section, important new allergens continue to be discovered, but the major focus as in the last couple of years was on working out how component-resolved approaches can improve diagnosis and management of food and venom allergy.

Delving into cornerstones of hypersensitivity to antineoplastic and biological agents: value of diagnostic tools prior to desensitization

BACKGROUND

Evidence regarding drug provocation test (DPT) with antineoplastic and biological agents is scarce. Our aim was to assess the usefulness of including DPT as a paramount gold standard diagnostic tool (prior to desensitization).

METHODS

Prospective, observational, longitudinal study with patients who, during a 3-year period, were referred to the Desensitization Program at Ramon y Cajal University Hospital. Patients underwent a structured diagnostic protocol by means of anamnesis, skin tests (ST), risk assessment, and DPT. Oxaliplatin-specific IgE was determined in oxaliplatin-reactive patients (who underwent DPT regardless of oxaliplatin-specific IgE results). Univariate analysis and multivariate analysis were used to identify predictors of the final diagnosis among several variables.

RESULTS

A total of 186 patients were assessed. A total of 104 (56%) patients underwent DPT. Sixty-four percent of all DPTs were negative (i.e., hypersensitivity was excluded). Sensitivity for oxaliplatin-specific IgE (0.35 UI/l cutoff point) was 34%, specificity 90.3%, negative predictive value 45.9%, positive predictive value 85%, negative likelihood ratio 0.7, and positive likelihood ratio 3.5.

CONCLUSIONS

These are the first reported data based on more than 100 DPTs with antineoplastic and biological agents (paclitaxel, oxaliplatin, rituximab, infliximab, irinotecan, and other drugs). Implementation of DPT in diagnostic protocols helps exclude hypersensitivity (in 36% of all referred patients), and avoids unnecessary desensitizations in nonhypersensitive patients (30-56% of patients, depending on culprit-drug). Drug provocation test is vital to validate diagnostic tools; consequently, quality data are shown on oxaliplatin-specific IgE and oxaliplatin-ST in the largest series of oxaliplatin-reactive patients reported to date (74 oxaliplatin-reactive patients). Identifying phenotypes and predictors of a diagnosis of hypersensitivity may be helpful for tailored plans.

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.

Tolerance to COX-2 inhibitors in children with hypersensitivity to nonsteroidal anti-inflammatory drugs

BACKGROUND

Hypersensitivity to nonsteroidal anti-inflammatory drugs (NSAIDs) can affect children, with the mechanism proposed being inhibition of the cyclooxygenase enzyme-1 (COX-1). In these patients nonchemically related NSAIDs, including COX-2 inhibitors, can induce the reaction, hampering treatment of fever and inflammatory processes.

OBJECTIVES

To analyse retrospectively tolerance to etoricoxib, a selective COX-2 inhibitor, and to meloxicam, a preferential COX-2 inhibitor, in children with hypersensitivity to NSAIDs.

METHODS

Clinical records of children (aged 1-14 years) diagnosed with hypersensitivity reactions to NSAIDs from January 2006 to January 2013 were included. The diagnosis was confirmed by oral drug provocation test (DPT) with the culprit NSAIDs and acetylsalicylic acid (ASA). Tolerance to paracetamol, etoricoxib and meloxicam was also evaluated.

RESULTS

The study included 41 children with a positive DPT with ASA and the culprit NSAID. DPT with paracetamol and etoricoxib was negative in all children, although two (4.9%) children developed a reaction after the administration of meloxicam.

CONCLUSIONS

These data indicate that both etoricoxib and meloxicam are good alternatives for treatment in older children with hypersensitivity to NSAIDs.

Nonsteroidal anti-inflammatory drugs are major causes of drug-induced anaphylaxis

BACKGROUND

Drugs are responsible for 40% to 60% of anaphylactic reactions treated in the emergency department. A global research agenda to address uncertainties in anaphylaxis includes studies that identify factors associated with morbidity and mortality.

OBJECTIVE

The present study investigated drug-induced anaphylaxis, etiologies, aggravating factors, and treatment.

METHODS

A total of 806 patients with adverse drug reactions were screened, and those who had a clinical diagnosis of anaphylaxis were included in the study. Clinical and demographic characteristics of anaphylaxis were described, including etiologies, pathophysiologic mechanisms involved in the reactions, and a personal history of atopy and asthma. Factors associated with disease severity also were identified.

RESULTS

Anaphylaxis was diagnosed in 117 patients (14.5%). The etiologies were defined in 76% of the cases, nonsteroidal anti-inflammatory drugs being the most frequent. Seventy-eight patients (66.7%) reported a previous reaction to the drug involved in the current reaction or to a drug from the same class and/or group. Epinephrine was used to treat 34.2% of patients who presented with anaphylaxis, and 40.8% of those with anaphylactic reactions with cardiovascular involvement. IgE-mediated reactions were associated with greater severity, manifested by the rates of cardiovascular dysfunction, hospitalization, and use of epinephrine.

CONCLUSIONS

The prevalence of anaphylaxis is high in patients who seek medical assistance for drug reactions, but its diagnosis is missed in emergency services, and adrenaline is underused. Drugs were prescribed to many patients despite a history of previous reaction. Nonsteroidal anti-inflammatory drugs were implicated in most cases of anaphylaxis induced by drugs, and IgE-mediated reactions were less frequent but more severe.