Clinical Characteristics of NSAID-induced Blended Reaction

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.

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.

Immunologic Basis of Type 2 Biologics for Severe Asthma

Asthma is a chronic airway inflammatory disease characterized by reversible airway obstruction and airway hyperreactivity to various environmental stimuli, leading to recurrent cough, dyspnea, and wheezing episodes. Regarding inflammatory mechanisms, type 2/eosinophilic inflammation along with activated mast cells is the major one; however, diverse mechanisms, including structural cells-derived and non-type 2/neutrophilic inflammations are involved, presenting heterogenous phenotypes. Although most asthmatic patients could be properly controlled by the guided treatment, patients with severe asthma (SA; classified as a treatment-refractory group) suffer from uncontrolled symptoms with frequent asthma exacerbations even on regular anti-inflammatory medications, raising needs for additional controllers, including biologics that target specific molecules found in asthmatic airway, and achieving the precision medicine for asthma. This review summarizes the immunologic basis of airway inflammatory mechanisms and current biologics for SA in order to address unmet needs for future targets.