Phenotypical characterization of children with hypersensitivity reactions to NSAIDs

Risk factors for drug hypersensitivity reactions in children

Drug hypersensitivity reactions are common in children. Risk factors predisposing to IgE-mediated drug allergies and delayed drug reactions are a matter of debate. Gender, age, previous reactions to the same drug or to another drug, reduced drug metabolism, chronic diseases, polypharmacy, drug doses are linked with the onset of hypersensitivity reactions in some children. Novel advances in genetic polymorphisms can rapidly change the approach to the prevention of reactions since gene testing can be a useful screening test for severe cutaneous adverse reactions. Viral infections may act as cofactors in susceptible individuals. Polypharmacy, high doses, repeated doses and parental route of administration are also risk factors. Clinicians should take into account risk factors to allow the risk-benefit balance to be maintained.

Diagnostic evaluation of hypersensitivity reactions to arylpropionic acid derivatives: a descriptive observational study focusing on clinical characteristics and potential risk factors in children

BACKGROUND

Arylpropionic acid derivatives (APs) are the main triggers of nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity. Data on clinical patterns and risk factors for AP hypersensitivity in children are quite limited.

AIM

To assess the clinical characteristics and potential risk factors for proven AP hypersensitivity in children.

METHOD

Patients with a history of AP hypersensitivity were retrospectively assessed using a standardized diagnostic algorithm. Children with confirmed hypersensitivity were defined as selective responders or cross-intolerants based on the result of drug provocation tests and further categorized according to the EAACI/ENDA classification. A multivariable logistic regression analysis was performed to analyze the potential risk factors for proven AP hypersensitivity.

RESULTS

A total of 166 patients (51.2% male, median age of six years) with a history of AP hypersensitivity were included. Ibuprofen (89.2%) was the most frequently reported AP in the patients' histories. The reported hypersensitivity of 40 (22.4%) patients was confirmed by diagnostic testing: eight (13.6%) patients with a history of reaction only to APs and 32 (29.9%) patients with a history of reactions to multiple NSAIDs, including chemically unrelated NSAIDs in addition to APs. Five (12.5%) patients were classified as selective responders and 35 (87.5%) were cross-intolerants. Overall, five (12.5%) of the confirmed cases could not be categorized according to the EAACI/ENDA classification. Older age (aOR: 1.11, 95% CI 1.02-1.21, p = 0.015), chronic urticaria as an underlying disease (aOR: 2.87, 95% CI 1.09-7.54, p = 0.033) and a history of anaphylaxis (aOR: 7.84, 95% CI 1.86-33.04, p = 0.005) were related to confirmed AP hypersensitivity.

CONCLUSION

Almost a quarter of children and adolescents were confirmed to have AP hypersensitivity. Older age, the presence of chronic urticaria and a history of anaphylaxis were potential risk factors for proven AP hypersensitivity.

Alternative Drug Safety in Children with Nonsteroidal Anti-Inflammatory Drug Hypersensitivity

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used in the pediatric age group as pain relievers, antipyretics and anti-inflammatory drugs. Since NSAIDs are used in many medical conditions, there is a need for alternative NSAIDs to be used safely in people with hypersensitivity reactions. Selective and partially selective COX-2 inhibitors and weak COX-1 inhibitors are generally used as safe alternative drugs. The aim of this study was to evaluate safe NSAIDs determined by oral provocation tests (OPTs) according to phenotypes in children with NSAID hypersensitivity reactions.

METHODS

The results of the oral provocation test performed with alternative NSAIDs (paracetamol, meloxicam, nimesulide, celecoxib) in patients followed up with the diagnosis of NSAID hypersensitivity reaction in the Pediatric Immunology and Allergy Department between January 2015 and February 2023 were evaluated retrospectively.

RESULTS

During the study period, 91 patients underwent OPTs with 109 alternative drugs 48 (52.7%) of whom were girls, with a median age of 15 years. 91 patients had a history of reactions to 117 drugs. As an alternative NSAID; OPT was performed with paracetamol in 58 patients, meloxicam in 44 patients, nimesulide in 5 patients, and celecoxib in 2 patients. Since 15 patients used paracetamol safely at home, no tests were performed with paracetamol. Reactions were observed in 3 of the 73 patients (4.1%) who underwent OPT with paracetamol and in 2 of the 44 (4.5%) who underwent OPT with meloxicam. Reactions to nimesulide were also observed in the latter 2 patients (2/5, 40%), but they appeared to tolerate celecoxib. No reaction was observed in the 2 patients who were tested with celecoxib.

CONCLUSION

Paracetamol, meloxicam, and nimesulide can be used as safe alternative drugs in most children with NSAID hypersensitivity. Selective COX-2 inhibitors should be tried as an alternative in patients who cannot tolerate them.

Design and synthesis of pterostilbene derivatives bearing triazole moiety that might treat DSS-induced colitis in mice through modulation of NF-κB/MAPK signaling pathways

In this study, a series of novel anti-inflammatory compounds with high activity and low toxicity were designed and synthesized based on the natural product pterostilbene skeleton. According to the strategy of pharmacophore combination, we introduced thiazole moiety into pterostilbene skeleton to design and synthesize a novel series of pterostilbene derivatives (a total of 41 compounds), and lipopolysaccharide (LPS)-treated RAW 264.7 cells were screened for anti-inflammatory activity and cytotoxicity. Among them, compound 8 was found to be the most active (against NO: IC50 = 0.6 μM) compared with pterostilbene and indomethacin. Anti-inflammatory mechanism studies revealed that compound 8 inhibited pro-inflammatory cytokines by blocking the NF-κB/MAPK signaling pathway in LPS-treated RAW 264.7 cells. In vivo experiments showed that compound 8 had a good relieving effect on DSS-induced acute colitis in mice, and also demonstrated a good safety in acute toxicity experiments. In conclusion, compound 8 may be a promising anti-inflammatory lead compound in the treatment of acute colitis.

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.

NSAID Hypersensitivity in the Pediatric Population: Classification and Diagnostic Strategies

Non-steroidal anti-inflammatory drugs (NSAIDs) are among the most frequently administered drugs, mainly for their anti-pyretic, but also for pain-relieving and anti-inflammatory effects in children. NSAIDs are composed of structurally divergent subgroups of drugs with similar pharmacological and adverse effects. Aspirin originates from salicin and was the first synthesized analgesic. As a prototype of NSAIDs; aspirin-induced hypersensitivity reactions were first reported, but subsequently, other phenotypes of hypersensitivity reactions were also described with aspirin and other NSAIDs. There are certain challenging aspects of NSAID-hypersensitivity in the pediatric population that need to be further investigated. These include the effect of age on drug metabolism and the natural history of the various phenotypes of NSAID-hypersensitivity, the effect of certain co-factors (infections, exercise) on NSAID-hypersensitivity, and diagnostic clinical and laboratory biomarkers clarifying the endotypes. In recent years, a non-negligible number of case series, studies and expert panel reports have been published in this field with some novel features and diagnostic modalities in the pediatric population. With the current review; the clinical phenotypes and diagnostic and management modalities of suspected NSAID-induced hypersensitivity reactions in childhood and adolescence were explained and updated by examining past and current publications.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Behind the scene: Paracetamol hypersensitivity in children

BACKGROUND

Paracetamol, a non-steroidal anti-inflammatory drug, is commonly being used for fever and pain relief worldwide. The aim of this study was to evaluate children with a suspected history of paracetamol hypersensitivity.

METHODS

Sixty patients who were referred to our clinic in between January 2015 and December 2018 with a suspected history of paracetamol hypersensitivity were included. Reactions were classified according to the European Network for Drug Allergy (ENDA)/Global Allergy and Asthma European Network classification and European Academy of Allergy and Clinical Immunology (EAACI)/ENDA Position Paper. Diagnoses were confirmed by skin tests and oral challenge tests (OCTs). In those with verified paracetamol hypersensitivity, an OCT with a strong COX-1 inhibitor was performed to classify the type of the reaction to refer as either selective or cross-intolerance hypersensitivity. A subsequent OCT with a selective COX-2 inhibitor was performed in those cross-intolerant patients to find out a safe alternative drug.

RESULTS

Sixty OCTs with paracetamol were performed to patients with a median age of 8.5 years, and hypersensitivity to paracetamol was verified in 8 patients. Four children were classified as selective responders, and 3 were classified as cross-intolerant after OCT with a COX-1 inhibitor. Overall, skin test positivity for paracetamol was detected in only one patient, in whom OCT with paracetamol was negative. In all 3 cross-intolerant patients, a safe alternative non-steroidal anti-inflammatory drug was identified after an OCT with a selective COX-2 inhibitor.

CONCLUSION

OCT stands as the gold-standard procedure in verifying the diagnosis of patients with paracetamol-induced drug hypersensitivity, as well as, in defining the type of reactions and finding out safe alternative drugs.

Drug Allergy in children: focus on beta-lactams and NSAIDs

Drug hypersensitivity reactions (DHRs) are adverse reactions to a drug. In children, most common drugs inducing such reactions include beta-lactams (BLs) and non-steroidal anti-inflammatory drugs (NSAIDs). The aim of the present work was to provide current knowledge on the management of DHRs in the pediatric population, focusing on BLs and NSAIDs hypersensitivity. The clinical feature of DHRs include immediate and non-immediate (delayed and accelerated) reactions, that may be severe or non-severe. A systematic approach to the patient based on the reported clinical history is essential to organize a safe and adapted allergy work-up. Skin tests are the first step to assess a possible DHRs, especially in immediate reactions to BLs. Drugs concentrations for these tests are standardized and validated. The drug provocation test remains the gold standard to reach a firm diagnosis. In selected cases, a therapeutic desensitization protocol may be proposed in children with a confirmed diagnosis of drug hypersensitivity. Clinicians should be aware of the diagnostic and therapeutic options, to provide the best management in children having experienced a history of DHR. (www.actabiomedica.it)

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.

Results of NSAID provocation tests and difficulties in the classification of children with nonsteroidal anti-inflammatory drug hypersensitivity

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in children and can frequently cause hypersensitivity reactions. Rates of confirmed NSAID hypersensitivity (NSAID-H) in children are low.

OBJECTIVE

To evaluate the results of drug provocation tests (DPTs) with NSAIDs and to evaluate the difficulties encountered in the classification of NSAID-H in children.

METHODS

The study included patients with suspected NSAID-H who were examined in our clinic between January 1, 2015, and December 31, 2018. Oral provocation tests with NSAIDs were performed and reactions were classified according to the European Academy of Allergy and Clinical Immunology position paper on NSAID-H.

RESULTS

A total of 243 patients (57.2% male patients) presented with suspected NSAID-H during the study period. Of these, 168 patients (69.1%) had a history of reaction to ibuprofen. Isolated skin involvement was the most frequent symptom (86%). A total of 238 DPTs were performed with the suspected agents and 34 had positive results. The families of 12 patients refused provocation testing with the suspected agent or aspirin and these patients could not be diagnosed. Of the 231 patients, 47 patients (20.3%) received a diagnosis of NSAID-H. Twenty patients with NSAID-H could not be classified because their guardians did not consent to further testing with aspirin.

CONCLUSION

Performing diagnostic tests is important in patients with no contraindications. Characterizing these reactions in children can be difficult because of the coexistence of indistinguishable symptoms in their history and DPTs, as well as the need for multiple provocation tests. Therefore, further research is needed on this subject.

Protocols for drug allergy desensitization in children

Introduction: When a drug hypersensitivity reaction is proven, desensitization protocols allow the reintroduction of the molecule in patients for whom such therapy is essential. Through drug desensitization (DDS), a temporary immune tolerance is maintained for the single course of a specific therapy. In pediatrics, indications for such a procedure include children with chronic diseases, severe infectious diseases and/or malignancies, who have a proven drug hypersensitivity.Areas covered: We ran a search on PubMed and Web of Science for papers on DDS and on DDS in children. Most protocols and recommendations on DDS focus on adults and have been adapted for children. The best candidates for desensitization are children with a history of immediate, IgE-mediated drug allergy, but this therapy may be applied also in nonallergic hypersensitivities and in non-immediate reactions. Most protocols in literature focus on antibiotics, especially beta-lactams, on chemotherapeutic agents, and on monoclonal antibodies.Expert opinion: Pediatric allergists should cooperate with specialists in infectious diseases and onco-hematology to provide DDS to children in need. Standardized protocols and international guidelines are still needed to optimize such treatment and to implement it in clinical daily practice.

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.

Pediatric Drug Allergies: Updates on Beta-Lactam, Nonsteroidal Anti-Inflammatory Drug, and Chemotherapeutic Reactions

Adverse drug reactions are frequently reported in pediatric patients. In this review article, the authors discuss pediatric drug allergies with emphasis on the most common culprits, beta-lactam antibiotics and non-steroidal anti-inflammatory drugs. The authors also discuss reactions to non-beta-lactam antibiotics and chemotherapeutics. Skin testing has not yet been validated for many drugs, although notable exceptions include penicillin and carboplatin. The gold standard for diagnosis in most cases remains drug challenge, and the need for penicillin skin testing prior to oral provocation challenge has been questioned in recent studies. Successful desensitizations have also been reported with several drugs.

Management of chronic urticaria in children: a clinical guideline

The aim of this guidance is to provide recommendations to clinicians and other interested parties on chronic urticaria in children. The Italian Society for Pediatrics (SIP), the Italian Society for Allergy and Immunology (SIAIP), the Italian Society for Pediatric dermatology (SIDerP) convened a multidisciplinary panel that prepared clinical guidelines for diagnosis and management of chronic urticaria in childhood. Key questions on epidemiology, natural history, diagnosis, and management were developed. The literature was systematically searched and evaluated, recommendations were rated and algorithms for diagnosis and treatment were developed. The recommendations focus on identification of diseases and comorbidities, strategies to recognize triggering factors, improvement of treatment by individualized care.

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.

Recent developments in drug hypersensitivity in children

Introduction: Drug allergy is an important public health problem that causes 0.4-10.3% of hospital admissions in children. The epidemiology, clinical spectrum, diagnosis, and management of drug hypersensitivity reactions (DHRs) differ in pediatric and adult patients. However, the same algorithms used in adults have often been applied in the pediatric population due to a lack of evidence in the literature. Areas covered: In this review, we aimed to discuss recent developments in the area of pediatric DHRs based on the growing body of literature advancing our understanding of the epidemiology, clinical aspects, and diagnostic approaches to DHRs in children. Expert opinion: Misdiagnosis, under-diagnosis, and self-diagnosis are common problems related to drug allergies in children. Viral infections are particularly frequent in children and make diagnosis difficult. Identifying true DHR is a key step in the management of drug allergy in children. Therefore, a complete allergy work-up with standardized drug allergy tests is necessary. In order to eliminate non-standardized tests, future studies including larger numbers of children should be conducted to determine more accurate standardized tests for diagnosing DHRs in the pediatric population.

Characteristics of NSAID-induced hypersensitivity reactions in childhood

Non-steroidal anti-inflammatory drugs (NSAIDs) are available as over-the-counter drugs, and they are commonly used in children for their antipyretic, analgesic, and anti-inflammatory effects. NSAIDs are among the most frequently reported drugs associated with hypersensitivity reactions and even with anaphylaxis. A complete evaluation of the patients based on reported clinical manifestations, timing of the reaction, the presence of underlying disease, and reactions to other NSAIDs allows clinicians to stratify children with a history of reaction to NSAIDs. Although NSAID-induced hypersensitivity reactions have mainly been investigated in adults, recent studies have aimed to explore their epidemiology in the pediatric population. This review will cover the current understanding of clinical manifestations, the risk factors, and the different phenotypes of NSAID-induced hypersensitivity reactions with a comprehensive overview of the epidemiologic data from past to present and the practical approach to the management of NSAID hypersensitivity in children and adolescents.

Pediatric drug hypersensitivity: which diagnostic tests?

Along with the anamnesis and clinical evaluation, diagnostic tests are one of the mainstream key points in the evaluation and management of drug hypersensitivity reactions (DHR). A wide knowledge gap, both in diagnosis and management of pediatric DHR, must be filled.  Only a few published studies evaluated sensitivity and specificity of skin and in vitro tests in children. However, selected case series show that diagnostic work-up for adults could be useful, with some limitations, in pediatric age. Indeed, despite improvement in in vivo and in vitro diagnosis, drug provocation test remains the gold standard in pediatric age, too. Unmet needs in children include multi-centric studies on incidence of DHR, utility and feasibility of in vivo and in vitro diagnostic tests and specifically dedicated guidelines for the diagnosis and management of DHR in children.

[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.

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.

Nonsteroidal anti-inflammatory drug hypersensitivity in the Asia-Pacific

Nonsteroidal anti-inflammatory drug (NSAID) hypersensitivity reactions (HSRs) are often nonimmunologically mediated reactions which present with immediate HSR type manifestations. These are mediated by cyclooxygenase inhibition resulting in shunting towards the excessive production of leukotrienes. Important disease associations include asthma, nasal polyposis, and chronic spontaneous urticaria, especially among adults. The European Network on Drug Allergy/Global Allergy and Asthma European Network 2013 classification of NSAID HSR comprises nonselective HSR i.e., NSAID exacerbated respiratory disease (NERD), NSAIDs exacerbated cutaneous disease (NECD), NSAIDs induced urticarial-angioedema (NIUA); and selective (allergic) HSR i.e., single NSAID induced urticaria/angioedema or anaphylaxis, NSAIDs-induced delayed HSR. Much of the literature on genetic associations with NSAID HSR originate from Korea and Japan; where genetic polymorphisms have been described in genes involved in arachidonic acid metabolism, basophil/mast cell/eosinophil activation, various inflammatory mediators/cytokines, and different HLA genotypes. The Asian phenotype for NSAID HSR appears to be predominantly NIUA with overlapping features in some adults and children. NECD also appears to be more common than NERD, although both are not common in the Asian paediatric population. Between adults and children, children seem to be more atopic, although over time when these children grow up, it is likely that the prevalence of atopic adults with NSAID HSR will increase. Low-dose aspirin desensitization has been shown to be effective in the treatment of coronary artery disease, especially following percutaneous coronary intervention.

EAACI/ENDA Position Paper: Diagnosis and management of hypersensitivity reactions to non-steroidal anti-inflammatory drugs (NSAIDs) in children and adolescents

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used in the pediatric population as antipyretics/analgesics and anti-inflammatory medications. Hypersensitivity (HS) reactions to NSAID in this age group, while similar to adults, have unique diagnostic and management issues. Although slowly accumulating, published data in this age group are still relatively rare and lacking a unifying consensus. This work is a summary of current knowledge and consensus recommendations utilizing both published data and expert opinion from the European Network of Drug Allergy (ENDA) and the Drug Hypersensitivity interest group in the European Academy of Allergy and Clinical Immunology (EAACI). This position paper summarizes diagnostic and management guidelines for children and adolescents with NSAIDs hypersensitivity.

Aspirin and Nonsteroidal Antiinflammatory Drugs Hypersensitivity and Management

Aspirin and nonsteroidal antiinflammatory drugs (NSAIDs) are widely used in the United States and throughout the world for a variety of indications. Several unique hypersensitivity syndromes exist to this class of medications, making them one of the common reasons for consultation to the allergist. The lack of any laboratory-based diagnostic studies to assist in identifying the culprits in these reactions make evaluation of aspirin and NSAID hypersensitivity challenging. Identifying patients appropriate for oral challenge and/or desensitization protocols is the standard pragmatic approach to this issue when it arises.

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.