Epidemiology of hypersensitivity drug reactions

Drug hypersensitivity reactions: review of the state of the science for prediction and diagnosis

Drug hypersensitivity reactions (DHRs) are a type of adverse drug reaction that can occur with different classes of drugs and affect multiple organ systems and patient populations. DHRs can be classified as allergic or non-allergic based on the cellular mechanisms involved. Whereas nonallergic reactions rely mainly on the innate immune system, allergic reactions involve the generation of an adaptive immune response. Consequently, drug allergies are DHRs for which an immunological mechanism, with antibody and/or T cell, is demonstrated. Despite decades of research, methods to predict the potential for a new chemical entity to cause DHRs or to correctly attribute DHRs to a specific mechanism and a specific molecule are not well-established. This review will focus on allergic reactions induced by systemically administered low-molecular weight drugs with an emphasis on drug- and patient-specific factors that could influence the development of DHRs. Strategies for predicting and diagnosing DHRs, including potential tools based on the current state of the science, will also be discussed.

Drug-induced hypersensitivity reactions in a Lebanese outpatient population: A decade-long retrospective analysis (2012-2021)

Background

Drug hypersensitivity reactions (DHRs) are becoming more common as a result of increasing prevalence and case complexity. Allergists and clinical immunologists worldwide are challenged daily to adequately diagnose and manage these reactions. Data in the literature regarding DHR outpatient consultations are scarce worldwide, limited in the Middle East, and currently unavailable in Lebanon.

Objective

This retrospective study aimed to evaluate the characteristics of all reported DHRs over 10 years in a tertiary-care allergy clinic in Lebanon.

Methods

We conducted a decade-long (2012-21) retrospective analysis of the archived medical records of patients with a history of DHRs. Demographics, clinical history, diagnostic tools, and characteristics of the DHRs were collected and analyzed.

Results

A total of 758 patients experienced DHRs to therapeutic molecules provided for ambulatory care. Our results identified 72 medications. The most frequently implicated drug classes included β-lactam antibiotics (53.8%), followed closely by nonsteroidal anti-inflammatory drugs (48.9%). Of the 758 patients, 32.6% reported DHRs to multiple molecules, and 11.8% reported concomitant DHRs to 1 or several molecules provided in the perioperative setting. Of those, opioids and neuromuscular blocking agents were the 2 most common therapeutic classes. Furthermore, we evaluated the cross-reactivity between molecules of the same class. In neuromuscular blocking agents, rocuronium and cisatracurium were the most commonly cross-reactive, and for opioids, the most common association we recorded was with morphine and pethidine.

Conclusion

Our findings constitute the first step toward a more comprehensive evaluation of the clinical characteristics of DHRs in Lebanon.

Genetic Susceptibility of HLA Alleles to Non-Steroidal Anti-Inflammatory Drug Hypersensitivity in the Taiwanese Population

BACKGROUND

Human leukocyte antigen (HLA) genes are important in many immune processes and contribute to many adverse drug reactions. Whether genetic variations in the HLA region are associated with non-steroid anti-inflammatory drug (NSAID) hypersensitivity remains uncertain. Therefore, the aim of our study was to identify HLA genetic variations in patients with NSAID hypersensitivity in the Taiwanese population.

METHODS

This hospital-based, retrospective case-control study enrolled 37,156 participants with NSAID exposure from the Taiwan Precision Medicine Initiative (TPMI), who were all genotyped and imputed to fine map HLA typing. Our study assigned 1217 cases to the NSAID allergy group and 12,170 controls to a matched group. Logistic regression analyses were utilized to explore associations between HLA alleles and NSAID hypersensitivity.

RESULTS

Overall, 13,387 patients were genotyped for eight major HLA alleles. Allele frequencies were different between the two groups. In the NSAID allergy group, the genotype frequencies of HLA-A*02:01, HLA-A*34:01, and HLA-DQA1*06:01 were found to be markedly elevated compared to the control group, a significance that persisted even after applying the Bonferroni correction. Furthermore, the risk of NSAID allergy demonstrated a significant association with HLA-A*02:01 (OR = 1.29, p < 0.001) and HLA-A*34:01 (OR = 9.90, p = 0.001), in comparison to their respective counterparts. Notably, the genotype frequency of HLA-B*46:01 exhibited a significant increase in the severe allergy group when compared with the mild allergy group.

CONCLUSIONS

We identified HLA genotypes linked to the onset and severity of NSAID hypersensitivity. Our findings establish a basis for precision prescription in future clinical applications.

Internalizing disorders as a mediator of the association between adverse childhood experiences and perceived medication intolerance or poly-allergy

OBJECTIVES

There is a well-established link between adverse childhood events, mental health, and physical health conditions. There is also a large literature showing the relationship between medication intolerance or allergies, and poor health outcomes. However, less is understood about the role of medication intolerance and adverse childhood events. Thus, the present study examines the relationship between adverse childhood events, internalizing disorders (depression, anxiety) and medication intolerance.

METHOD

Three hundred forty-nine participants were recruited from 11 primary care practices and health networks located in a large, Midwestern metropolitan area. Unrelated linear and Poisson regression was used to determine whether internalizing disorders, such as depression and anxiety, mediated the relationship between adverse childhood experiences (ACEs) and allergies to medications, accounting for error terms in regression equations that were correlated.

RESULTS

Results indicated an association between ACEs and number of allergies to medication, whereby ACEs was associated with depression, anxiety and number of allergies. Sensitivity analysis confirmed these findings. There was a small but significant indirect effect of anxiety on allergies to medication after bootstrapping.

CONCLUSION

This study found that inflammatory responses occurring because of trauma and depression may be increasing medication allergies. However, given the size of the sample, more research is needed to confirm these results. Implications for healthcare providers are discussed.

The epithelial barrier: The gateway to allergic, autoimmune, and metabolic diseases and chronic neuropsychiatric conditions

Since the 1960 s, our health has been compromised by exposure to over 350,000 newly introduced toxic substances, contributing to the current pandemic in allergic, autoimmune and metabolic diseases. The "Epithelial Barrier Theory" postulates that these diseases are exacerbated by persistent periepithelial inflammation (epithelitis) triggered by exposure to a wide range of epithelial barrier-damaging substances as well as genetic susceptibility. The epithelial barrier serves as the body's primary physical, chemical, and immunological barrier against external stimuli. A leaky epithelial barrier facilitates the translocation of the microbiome from the surface of the afflicted tissues to interepithelial and even deeper subepithelial locations. In turn, opportunistic bacterial colonization, microbiota dysbiosis, local inflammation and impaired tissue regeneration and remodelling follow. Migration of inflammatory cells to susceptible tissues contributes to damage and inflammation, initiating and aggravating many chronic inflammatory diseases. The objective of this review is to highlight and evaluate recent studies on epithelial physiology and its role in the pathogenesis of chronic diseases in light of the epithelial barrier theory.

[Antibiotic allergies: targeted approach in suspected β‑lactam allergy]

Allergic reactions to antibiotics belong to hypersensitivity drug reactions and can trigger both immunoglobulin E-mediated symptoms and T cell-mediated symptoms. Skin manifestations are the most common symptoms. Although reporting a penicillin allergy results in considerable restrictions in the treatment of acute infections, which may be associated with poor treatment outcomes, in most cases the label 'penicillin allergy' is not called into question or critically reviewed. However, in 85-90% of patients, 'penicillin allergy' constitutes a mislabeling of a non-specific intolerance reaction that does not pose a risk to the patient when re-exposed to penicillins. Careful history taking, an evaluation of manifestations in the past, and easy-to-perform initial diagnostic steps are crucial in differentiating non-specific intolerance reactions from penicillin allergy sensu stricto. Thus, a penicillin de-labeling strategy allows for optimized antibiotic therapy in the event of a future infection. Although allergic cross-reactivity between different β‑lactam antibiotics can occur, the risk for a severe cross-reactivity is dependent on chemical properties of the specific β‑lactam. Published cross-reactivity tables can help in risk stratification and choice of alternative β‑lactam agents.

Type IV Hypersensitivity Reaction after Cyanoacrylate Venous Closure

BACKGROUND

Nonthermal endovenous closure techniques are routinely utilized to treat superficial axial venous reflux. Cyanoacrylate closure is a safe and effective modality implemented for truncal closure. However, an adverse reaction of type IV hypersensitivity (T4H), unique to cyanoacrylate, is a known risk. This study aims to evaluate the real-world incidence of T4H and examine risk factors that may predispose its development.

METHODS

A retrospective review between 2012- and 2022 was performed at four tertiary US institutions to examine patients who underwent cyanoacrylate vein closure of their saphenous veins. Patient demographics, comorbidities, CEAP (Clinical [C], Etiological [E], Anatomical [A], and Pathophysiological [P]) classification, and periprocedural outcomes were included. The primary endpoint was development of T4H post procedure. Logistic regression analysis for risk factors predictive of T4H was performed. Variables with a P-value of <0.05 were deemed significant.

RESULTS

595 patients underwent 881 cyanoacrylate venous closures. Mean age was 66.2 ± 14.9, and 66% of patients were female. There were 92 (10.4%) T4H events in 79 (13%) patients. Oral steroids were administered to 23% for persistent and/or severe symptoms. There were no systemic allergic reactions to cyanoacrylate. Multivariate analysis revealed younger age (P = 0.015), active smoking status (P = 0.033), and CEAP 3 (P < 0.001) and 4 (P = 0.005) classifications as independent risk factors associated with development of T4H.

CONCLUSIONS

This real-world multicenter study shows the overall incidence of T4H to be 10%. CEAP 3 and 4 patients of younger age and smokers predicted a higher risk of T4H to cyanoacrylate.

Aspirin-induced urticaria in a recently diagnosed ischemic stroke patient: A case report and literature review

KEY CLINICAL MESSAGE

NSAIDs may be rare but an important cause of urticarial which should not be missed.

ABSTRACT

The aspirin and urticaria correlation has not been fully understood. The pharmacological inference is suspected to be the diversion of arachidonic acid metabolism. Aspirin sensitivity can aggravate preexisting chronic urticaria and in some instances causes acute urticaria. We report a case of a 53-year-old male, recently diagnosed with a stroke, who presented with complaints of multiple rashes over the trunk and upper extremities with aspirin. NSAIDs induced urticarial are usually neglected by physicians during diagnosis.

Preventive effect of dexamethasone premedication on the development of infusion-related reaction in breast cancer patients receiving trastuzumab

AIM

To clarify the incidence and risk factors of infusion-related reactions (IRRs) caused by trastuzumab in breast cancer patients and verify the preventive effects of dexamethasone.

METHODS

All breast cancer patients newly treated with trastuzumab at the Osaka Medical and Pharmaceutical University Hospital from 1 January 2017 to 31 December 2020 were included. The electronic medical records were retrospectively reviewed. The outcome measure was the occurrence of IRRs of grade 1 or higher during trastuzumab infusion. Only dexamethasone and anticancer drugs administered concomitantly before trastuzumab were used as explanatory variables.

RESULTS

The 176 patients included in the study received 2320 infusions. Fifty-eight patients (33.0%) experienced IRRs, and IRRs occurred in 80 (3.4%) of the total 2320 infusions. Owing to the hierarchical structure of the data, the independence of the observed values was evaluated using the intraclass correlation coefficient. Multivariate multilevel logistic regression analysis showed that premedication with dexamethasone lowered the risk of trastuzumab-induced IRRs (mg, per 1 unit, odds ratio [OR] = 0.61, 95% confidence interval [95% CI] 0.43-0.85, P = .003). In addition, preoperative status (OR = 38.9, 95% CI 5.4-278.7, P < .001) and high-dose trastuzumab (mg/kg, per 1 unit, OR = 60.6, 95% CI 20.1-182.9, P < .001) were independent risk factors for IRRs.

CONCLUSION

The results of this study suggest that premedication with dexamethasone exhibits preventive effects on trastuzumab-induced IRRs in breast cancer patients. Future studies are needed to determine the optimal dose of dexamethasone to prevent IRRs and the impact of dexamethasone on the efficacy of trastuzumab in breast cancer.

Pearls for practice from the 2022 joint task force drug allergy practice parameter

PURPOSE OF REVIEW

To review updated recommendations in the 2022 Drug Allergy Practice Parameters for the evaluation and management of drug hypersensitivity reactions.

RECENT FINDINGS

Adverse drug reactions have become increasingly prominent with the advent of new and emerging pharmacologic therapies. Hypersensitivity reactions encompass a significant proportion of adverse drug reactions and negatively impact both the individual patient and overall health system. Reactions are heterogeneous in presentation and may be immediate (onset of symptoms ≤6 h) or delayed (onset of symptoms >6 h to months) after drug exposure. The 2022 Drug Allergy Practice Parameter provides consensus-based statements for evaluation of hypersensitivity reactions to antibiotics, NSAIDs, cancer chemotherapies, immune checkpoint inhibitors, biologics, and excipients. In general, the guideline highlights the importance of patient history in elucidating the phenotype and severity of the index reaction. Drug challenge remains the gold standard for diagnosis and is increasingly favored over skin testing in patients with nonsevere, nonanaphylactic drug reaction histories.

SUMMARY

The 2022 Drug Allergy Practice Parameter provides an updated framework for physicians to reference in clinical practice when managing patients with drug hypersensitivity reactions.

[Antibiotic allergies: targeted approach in suspected β‑lactam allergy]

Allergic reactions to antibiotics belong to hypersensitivity drug reactions and can trigger both immunoglobulin E-mediated symptoms and T cell-mediated symptoms. Skin manifestations are the most common symptoms. Although reporting a penicillin allergy results in considerable restrictions in the treatment of acute infections, which may be associated with poor treatment outcomes, in most cases the label 'penicillin allergy' is not called into question or critically reviewed. However, in 85-90% of patients, 'penicillin allergy' constitutes a mislabeling of a non-specific intolerance reaction that does not pose a risk to the patient when re-exposed to penicillins. Careful history taking, an evaluation of manifestations in the past, and easy-to-perform initial diagnostic steps are crucial in differentiating non-specific intolerance reactions from penicillin allergy sensu stricto. Thus, a penicillin de-labeling strategy allows for optimized antibiotic therapy in the event of a future infection. Although allergic cross-reactivity between different β‑lactam antibiotics can occur, the risk for a severe cross-reactivity is dependent on chemical properties of the specific β‑lactam. Published cross-reactivity tables can help in risk stratification and choice of alternative β‑lactam agents.

Incidence and Economic Burden of Adverse Drug Reactions in Hospitalization: A Prospective Study in Korea

BACKGROUND

Adverse drug reactions (ADRs) are escalating, and their socioeconomic burden is increasing. However, large-scale prospective studies investigating ADRs during hospitalization are rare in Korea. We prospectively investigated the incidence, characteristics, and economic burden of ADRs in hospitalized patients based on electronic medical records (EMRs).

METHODS

Among patients admitted to three hospitals from October 2016 to October 2017, 5,000 patients were randomly selected and prospectively observed during hospitalization. Research nurses monitored and detected patients who had symptoms, signs, or laboratory findings suspicious for ADRs using an EMR-based detection protocol. Next, allergy and ADR specialists reviewed the medical records to determine the relationship between adverse reactions and drugs. Cases in which a causal relationship was certain, probable/likely, or possible were included in the ADR cases. Clinically meaningful ADR cases or those leading to prolonged hospitalization were defined as significant ADRs.

RESULTS

ADRs occurred in 510 (10.2%) patients. The mean length of hospital stay was approximately 5 days longer in patients with ADRs. Opioids accounted for the highest percentage of total ADRs. Significant ADRs were observed in 148 (3.0%) patients. Antibiotics accounted for the highest percentage of significant ADRs. Drug hypersensitivity reactions (DHRs) occurred in 88 (1.8%) patients. Antibiotics accounted for the highest percentage of DHRs. The average medical expenses for one day of hospitalization per patient were highest in significant ADRs, followed by non-significant ADRs, and non-ADRs.

CONCLUSION

ADRs in hospitalized patients are an important clinical issue, resulting in a substantial socioeconomic burden. EMR-based strategy could be a useful tool for ADR monitoring and early detection.

Delayed Drug Hypersensitivity Reactions: Molecular Recognition, Genetic Susceptibility, and Immune Mediators

Drug hypersensitivity reactions are classified into immediate and delayed types, according to the onset time. In contrast to the immediate type, delayed drug hypersensitivity mainly involves T lymphocyte recognition of the drug antigens and cell activation. The clinical presentations of such hypersensitivity are various and range from mild reactions (e.g., maculopapular exanthema (MPE) and fixed drug eruption (FDE)), to drug-induced liver injury (DILI) and severe cutaneous adverse reactions (SCARs) (e.g., Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP)). The common culprits of delayed drug hypersensitivity include anti-epileptics, antibiotics, anti-gout agents, anti-viral drugs, etc. Delayed drug hypersensitivity is proposed to be initiated by different models of molecular recognition, composed of drug/metabolite antigen and endogenous peptide, HLA presentation, and T cell receptor (TCR) interaction. Increasing the genetic variants of HLA loci and drug metabolic enzymes has been identified to be responsible for delayed drug hypersensitivity. Furthermore, preferential TCR clonotypes, and the activation of cytotoxic proteins/cytokines/chemokines, are also involved in the pathogenesis of delayed drug hypersensitivity. This review provides a summary of the current understanding of the molecular recognition, genetic susceptibility, and immune mediators of delayed drug hypersensitivity.

Non-steroidal anti-inflammatory drug-induced anaphylaxis infrequent in 388 patients with mastocytosis: A two-center retrospective cohort study

Background

Anaphylaxis is a well-known feature of mastocytosis, particularly in relation to hymenoptera venom stings. It is therefore hypothesized that mastocytosis patients may also be predisposed to severe hypersensitivity reactions to certain medications including non-steroidal anti-inflammatory drugs (NSAIDs). For this reason, these patients are usually discouraged from using these drugs. The current study aimed to determine the prevalence and evaluate the severity of NSAID-related hypersensitivity reactions among patients with mastocytosis.

Methods

A retrospective study was conducted among a total of 388 (≥18 years old) consecutive patients from two independent European mastocytosis centers, in Sweden and Italy. Patients underwent a thorough allergy work-up where self-reported NSAID-hypersensitivity reactions were re-evaluated by an allergist in the first cohort (202 patients) and results were validated in the second cohort (186 patients).

Results

Overall frequency of NSAID-hypersensitivity was 11.3% in the total study cohort. Most patients reacted with cutaneous symptoms (89%), whereas severe hypersensitivity reactions were infrequent with only 11 patients (2.8%) experiencing anaphylaxis. All NSAID-related hypersensitivity reactions had occurred before mastocytosis was diagnosed. There was no difference between the groups regarding gender, baseline tryptase levels or presence of atopy, asthma/rhinitis.

Conclusion

Our study indicates an approximate 4-fold increased prevalence of NSAID hypersensitivity among mastocytosis patients compared to the general population. However, most NSAID reactions were limited to the skin as the prevalence of overall anaphylaxis was infrequent. Our results support that mastocytosis patients with a known tolerance to NSAIDs can continue using these medications without special precautions, whereas those with a prior reaction to NSAIDs should undergo thorough allergy work-up, including drug challenges.

LTT and HLA testing as diagnostic tools in Spanish vancomycin-induced DRESS cases: A case-control study

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe T-cell-mediated off-target adverse reaction. DRESS cases caused by vancomycin have often been reported. The HLA-A*32:01 allele has been associated with genetic susceptibility to vancomycin-induced DRESS in US citizens of European descent. We have analyzed the association of the HLA-A*32:01 allele in 14 Spanish DRESS cases in which vancomycin was suspected as the culprit drug, and the lymphocyte transformation test (LTT) as an in vitro assay to evaluate vancomycin sensitization. The results were compared to vancomycin-tolerant control donors. LTT was performed in 12 DRESS cases with PBMCs from resolution samples available and in a group of 12 tolerant donors. ROC curves determined that LTT is a suitable tool to identify patients sensitized to vancomycin (AUC = 0.9646; p < 0.0001). When a stimulation index >3 was regarded as a positive result, contingency tables determined 91% sensitivity, 91.67% specificity, 91% positive predictive value, and 91.67% negative predictive value (p = 0.0001, Fisher’s exact test). The HLA A*32:01 allele was determined by an allele-specific PCR assay in 14 cases and 25 tolerant controls. Among the DRESS cases, five carriers were identified (35.7%), while it was detected in only one (4%) of the tolerant donors, [odds ratio (OR) = 13.33; 95% CI: 1.364–130.3; p = 0.016]. The strength of the association increased when only cases with positive LTT to vancomycin were considered (OR = 24.0; 95% CI: 2.28–252.6; p = 4.0 × 10⁻³). Our results confirm the association of the risk allele HLA-A*32:01 with vancomycin-induced DRESS in Spanish cases, and support LTT as a reliable tool to determine vancomycin sensitization.

Perinatal outcome and long-term infectious hospitalizations of offspring born to women with known drug allergy

PROBLEM

Maternal drug allergy has been associated with altered immune status and an inflammatory environment, which may affect the risk of future infectious diseases in the offspring.

OBJECTIVES

We aimed to evaluate perinatal outcomes and long-term infectious hospitalization in the offspring of women with documented drug allergy.

METHOD OF STUDY

The study was conducted at the Soroka University Medical Center, a tertiary medical center. For perinatal outcomes, generalized estimation equation (GEE) models were used controlling for maternal age, maternal diabetes mellitus, smoking, and hypertensive disorders. The study groups were followed until 18 years of age for infectious-related hospitalizations. A Kaplan-Meier survival-curve was used to compare cumulative incidence of long-term infectious hospitalizations. A Cox proportional hazards model was conducted to control for confounders.

RESULTS

During the study period, 243,682 deliveries met the inclusion criteria, of which 9,756 (4.0%) occurred in women with documented drug allergy. Using GEE, maternal drug allergy was found to be a significant independent risk factor for hypertensive disorders, diabetes mellitus, intra-uterine growth restriction (IUGR) and preterm delivery. Offspring also had significantly higher rates of long-term infectious hospitalizations. Kaplan-Meier survival-curves demonstrated significantly higher cumulative incidence rates of infectious hospitalization (log rank p<0. 001). In a Cox proportional hazards model, being born to a mother with documented a drug allergy was independently associated with infectious hospitalization of the offspring in the long-term.

CONCLUSIONS

Maternal documented drug allergy is independently associated with adverse perinatal outcome such as IUGR and preterm delivery and increased risk of long- term infectious hospitalization of the offspring. This article is protected by copyright. All rights reserved.

Distribution of HLA-B Alleles and Haplotypes in Qatari: Recommendation for Establishing Pharmacogenomic Markers Screening for Drug Hypersensitivity

Human leukocyte antigen (HLA) proteins are present at the cellular surface of antigen-presenting cells and play a crucial role in the adaptive immune response. Class I genes, specifically certain HLA-B alleles, are associated with adverse drug reactions (ADRs) and are used as pharmacogenetic markers. Although ADRs are a common causes of hospitalization and mortality, the data on the prevalence of HLA-B pharmacogenetics markers in Arab countries are scarce. In this study, we investigated the frequencies of major HLA-B pharmacogenomics markers in the Qatari population. Next-generation sequencing data from 1,098 Qatari individuals were employed for HLA-B typing using HLA-HD version 1.4.0 and IPD-IMGT/HLA database. In addition, HLA-B pharmacogenetics markers were obtained from the HLA Adverse Drug Reaction Database. In total, 469 major HLA-B pharmacogenetic markers were identified, with HLA-B*51:01 being the most frequent pharmacogenetic marker (26.67%) in the Qatari population. Moreover, HLA-B*51:01 is associated with phenytoin- and clindamycin-induced ADRs. The second most frequent pharmacogenetic marker was the HLA-B*58:01 allele (6.56%), which is associated with allopurinol-induced ADRs. The third most frequent pharmacogenetic marker was the HLA-B*44:03 allele, which is associated with phenytoin-induced ADRs. The establishment of a pharmacogenetics screening program in Qatar for cost effective interventions aimed at preventing drug-induced hypersensitivity can be aided by the highly prevalent HLA-B pharmacogenetic markers detected here.

Pathology of T-cell-mediated drug hypersensitivity reactions and impact of tolerance mechanisms on patient susceptibility

PURPOSE OF REVIEW

T-cell-mediated drug hypersensitivity is responsible for significant morbidity and mortality, and represents a substantial clinical concern. The purpose of this article is to focus on T-cell reactions and discuss recent advances in disease pathogenesis by exploring the impact of tolerance mechanisms in determining susceptibility in genetically predisposed patients.

RECENT FINDINGS

Certain drugs preferentially activate pathogenic T cells that have defined pathways of effector function. Thus, a critical question is what extenuating factors influence the direction of immune activation. A large effort has been given towards identifying phenotypic (e.g., infection) or genotypic (e.g., human leukocyte antigen) associations which predispose individuals to drug hypersensitivity. However, many individuals expressing known risk factors safely tolerate drug administration. Thus, mechanistic insight is needed to determine what confers this tolerance. Herein, we discuss recent clinical/mechanistic findings which indicate that the direction in which the immune system is driven relies upon a complex interplay between co-stimulatory/co-regulatory pathways which themselves depend upon environmental inputs from the innate immune system.

SUMMARY

It is becoming increasingly apparent that tolerance mechanisms impact on susceptibility to drug hypersensitivity. As the field moves forward it will be interesting to discover whether active tolerance is the primary response to drug exposure, with genetic factors such as HLA acting as a sliding scale, influencing the degree of regulation required to prevent clinical reactions in patients.

Antiepileptic Drug Adverse Cutaneous Reaction in Childhood

Antiepileptic drug (AED) side effects can result in treatment failure, morbidity, and mortality. Adverse cutaneous drug reactions (ACRs) frequently occur within the first 2 to 3 months of drug use. We wanted to discuss antiepileptic ACRs in childhood in this study. This was a study of 37 pediatric patients who were diagnosed with ACR and treated with AED in the last 5 years. Over a 5-year period, 37 (1.8%) of the 2,064 epilepsy patients had ACRs. There were 23 (62%) male patients and 14 (38%) female patients. Patients had a median age of 6 years (interquartile range: [IQR]: 3.5–10). The ACRs occurred in a median of 20 (IQR: 14–30) days. There were 28 (75%) patients receiving monotherapy and 9 (25%) patients receiving polytherapy. Overall, 22 (59.5%) of the 37 patients used aromatic drugs (AD), while 15 (40.5%) used nonaromatic drugs (NAD). Morbilliform eruptions accounted for the majority of ACRs (84%). Valproic acid (54%) was the most frequently used AED that resulted in ACRs. There was no significant difference in terms of eruption time, gender, or age between AD and NAD. Within 1 to 2 months of initiating a new AED, patients should be closely monitored for ACRs. If an ACR develops for one AED, greater caution should be taken when initiating the other AED. Although it is well established that ADs cause more skin reactions, we found that one of the NADs, valproic acid, causes more skin reactions.

Drug Investigation to Dampen the Comorbidity of Rheumatoid Arthritis and Osteoporosis via Molecular Docking Test

At present, most rheumatoid arthritis (RA) patients are at risk of osteoporosis (OP), which is increased by 1.5 times compared to non-RA individuals. Hence, we investigated overlapping targets related directly to the occurrence and development of RA and OP through public databases (DisGeNET, and OMIM) and literature. A total of 678 overlapping targets were considered as comorbid factors, and 604 out of 678 were correlated with one another. Interleukin 6 (IL-6), with the highest degree of value in terms of protein−protein interaction (PPI), was considered to be a core target against comorbidity. We identified 31 existing small molecules (< 1000 g/mol) as IL-6 inhibitors, and 19 ligands were selected by the 3 primary criteria (Lipinski’s rule, TPSA, and binding energy). We postulated that MD2-TLR4-IN-1 (PubChem ID: 138454798), as confirmed by the three criteria, was the key ligand to alleviate comorbidity between RA and OP. In conclusion, we described a promising active ligand (MD2-TLR4-IN-1), and a potential target (IL-6) against comorbidity of RA and OP, providing scientific evidence for a further clinical trial.

Exanthematous Drug Eruption to Intravenous Iron: A Case Report

The authors present a rare case of an exanthematous drug reaction to intravenous iron. Exanthematous drug eruptions, also called morbilliform or maculopapular drug rashes, can occur in first-time drug exposures and represent a subtype of delayed-type IV hypersensitivity reactions. 

This patient is a 49-year-old female with a history of iron deficiency anemia and hypothyroidism who presented to the emergency department after experiencing a diffuse whole-body maculopapular rash following ferumoxytol 510 mg intravenously received once two days prior to her presentation. A clinical examination was suspicious of an exanthematous drug eruption. The patient was treated with methylprednisolone 40 mg intravenously twice a day for three days, followed by prednisone 40 mg orally twice a day for two days with a steroid taper upon discharge. The patient’s rash resolved within five days of steroid treatment.

There is a high global prevalence of iron deficiency anemia for which intravenous iron replacement may be required. However, there is limited research addressing its adverse effects, particularly those that include delayed hypersensitivity reactions. This paper aims to alert healthcare professionals of a rare type of delayed hypersensitivity reaction to intravenous iron to better guide management in the clinical setting. 

EAACI guidelines: Anaphylaxis (2021 update)

Anaphylaxis is a clinical emergency which all healthcare professionals need to be able to recognize and manage. The European Academy of Allergy and Clinical Immunology Anaphylaxis multidisciplinary Task Force has updated the 2014 guideline. The guideline was developed using the AGREE II framework and the GRADE approach. The evidence was systematically reviewed and recommendations were created by weighing up benefits and harms. The guideline was peer-reviewed by external experts and reviewed in a public consultation. The use of clinical criteria to identify anaphylaxis is suggested with blood sampling for the later measurement of tryptase. The prompt use of intramuscular adrenaline as first-line management is recommended with the availability of adrenaline autoinjectors to patients in the community. Pharmacokinetic data should be provided for adrenaline autoinjector devices. Structured, comprehensive training for people at risk of anaphylaxis is recommended. Simulation training and visual prompts for healthcare professionals are suggested to improve the management of anaphylaxis. It is suggested that school policies reflect anaphylaxis guidelines. The evidence for the management of anaphylaxis remains mostly at a very low level. There is an urgent need to prioritize clinical trials with the potential to improve the management of patients at risk of anaphylaxis.

Biologics as treatment options for anaphylaxis

PURPOSE OF REVIEW

To provide the most recent insights in the use of biologicals in the treatment of patients with anaphylaxis.

RECENT FINDINGS

There is evidence that biologics such as omalizumab may be safe and effective in preventing anaphylactic reactions in patients at high risk mainly because of severe food allergy or desensitization procedures to food, airborne allergen, drugs, or hymenoptera venom.

SUMMARY

Further knowledge will guide the adoption and implementation of any new therapy including biologics for anaphylaxis according to the stratification of risk/benefits.

Rational Pharmacotherapy in Infectious Diseases: Issues Related to Drug Residues in Edible Animal Tissues

Simple Summary

Drug use is essential to treat diseases in food-producing animals. The most widely used drugs are antiparasitics and antimicrobials. They contribute to guaranteeing good-quality food in sufficient quantity for human consumption. When using veterinary medicines, it is essential to follow the instructions on the package label. Administering the correct dose by the indicated route in the animal species for which the drug is labeled is critical. After a pharmacological treatment is administered to livestock, a period (indicated on the label) must often elapse before the tissues from the treated animals can be consumed by humans. Veterinary drug residues are controlled by taking food samples to verify that drug concentrations do not exceed the permitted limits. This allows authorities to know if the medicine use is correct or if suitable corrective measures should be taken. When label’s directions are not followed, drug residues may appear in food. The residues exceeding the permitted limits established by the authorities can produce unfavorable consequences, mainly on the consumer’s health. The food trade and even the environment can be affected by drug residues in animal tissues. Therefore, the correct use of drugs in livestock is critical, which includes respecting the rules to avoid residues in food for human consumption.

Abstract

Drugs are used in veterinary medicine to prevent or treat animal diseases. When rationally administered to livestock following Good Veterinary Practices (GVP), they greatly contribute to improving the production of food of animal origin. Since humans can be exposed chronically to veterinary drugs through the diet, residues in food are evaluated for effects following chronic exposures. Parameters such as an acceptable daily intake (ADI), the no-observed-adverse-effect level (NOAEL), maximum residue limits (MRLs), and the withdrawal periods (WPs) are determined for each drug used in livestock. Drug residues in food exceeding the MRLs usually appear when failing the GVP application. Different factors related either to the treated animal or to the type of drug administration, and even the type of cooking can affect the level of residues in edible tissues. Residues above the MRLs can have a diverse negative impact, mainly on the consumer’s health, and favor antimicrobial resistance (AMR). Drug residue monitoring programmes are crucial to ensure that prohibited or authorized substances do not exceed MRLs. This comprehensive review article addresses different aspects of drug residues in edible tissues produced as food for human consumption and provides relevant information contributing to rational pharmacotherapy in food-producing animals.

Aspirin Desensitization: Implications for Acetylsalicylic Acid-Sensitive Pregnant Women

Low-dose acetylsalicylic acid (ASA) is widely used during pregnancy to prevent obstetric complications of placental dysfunction, such as preeclampsia, stillbirth and fetal growth restriction, and obstetric complications in pregnant women with antiphospholipid syndrome. ASA-sensitive pregnant women cannot benefit from the effects of ASA due to the possibility of severe or potentially life-threatening hypersensitivity reactions to ASA. ASA desensitization is a valuable and safe therapeutic option for these women, allowing them to start daily prophylaxis with ASA and prevent pregnancy complications. The authors discuss the recent advances in obstetric conditions preventable by ASA and the management of ASA hypersensitivity in pregnancy, including ASA desensitization. To encourage the implementation of ASA desensitization protocols in ASA-sensitive pregnant women, they also propose a practical approach for use in daily clinical practice.

Life-Threatening Non-Allergic Drug Hypersensitivity Reaction as a Very Rare Side Effect of Rivaroxaban Administration in the Netherlands

BACKGROUND

Anticoagulant therapy is indicated for the prevention and treatment of thromboembolic disease. Direct oral anticoagulants (DOACs) are frequently prescribed and Rivaroxaban is the most frequently administered DOAC in the Netherlands. Most side effects relate to hemorrhagic complications, however, also non-hemorrhagic side effect may be potentially life threatening.

CASE PRESENTATION

A 74-year-old man presented at the emergency department with a ruptured infrarenal abdominal aortic aneurysm for which open aneurysm repair was performed. Postoperatively, the patient developed neurological deficit, respiratory and circulatory failure following rivaroxaban administration, initiated for atrial fibrillation. Even though, the clinical signs resembled an anaphylactic reaction, the skin-prick test was negative and complications most likely resulted from a non-allergic drug hypersensitivity reaction.

CONCLUSION

This case report shows that non-allergic drug hypersensitivity reactions may mimic an anaphylactic reaction and can be potentially life threatening. In addition, severe non-hemorrhagic complications after rivaroxaban administration do occur and should be considered in case of acute clinical deterioration.

Current practice for diagnosing immediate drug hypersensitivity reactions in Korea

BACKGROUND/AIMS

Skin (STs) and drug provocation (DPTs) tests are essential for identifying the culprit drugs causing drug hypersensitivity reactions (DHRs). Several protocols have been developed for the identification of some culprit drugs, but they are neither thoroughly validated nor standardized. Furthermore, language barriers may impede the exchange of information necessary for test standardization.

METHODS

We searched the Korean literature for articles on drug hypersensitivity published from 1933 to 2016 using the KoreaMed search engine and archives of Korean journals. We reviewed and rated all articles according to the description of STs and DPTs.

RESULTS

Of the 632 articles obtained in our initial search, 34 had adequate descriptions of 15 STs and 22 DPTs. Up to 27 healthy control subjects in STs were enrolled to determine non-irritating concentrations. The concentrations used for intradermal tests were commonly a 1/10 dilution of those used for skin prick tests. The interpretations of the STs were mostly similar among researchers. For DPTs, most procedures were single-arm open-label tests of various drugs. The initial dose ranged from a quarter dose to a single therapeutic dose, depending on the severity of the original hypersensitivity reaction. The interval between doses was usually 30 to 60 minutes, and a positive reaction usually occurred within twice the time of the original reaction.

CONCLUSION

Efforts to distribute information are necessary to standardize protocols and better understand DHRs.

Drug Allergy Labels Lost in Translation: From Patient to Charts and Backwards

The current method of defining, reporting, assessment, labeling, delabeling, and reconciliation of adverse drug reactions (ADRs), and specifically immunologically mediated drug hypersensitivity reactions (HSRs), in electronic health records (EHRs) is inadequate and compromises care quality and safety. It is critical to accurately and succinctly report the signs and symptoms associated with ADRs and suspected HSRs to enable clinicians to determine the plausible reaction type and help guide appropriate future management plans. Despite the current limitations of the EHR allergy module, we must encourage improved clinical documentation and demand technological improvements. Telehealth methods have been shown to be valuable in the assessment of ADRs and HSRs, particularly in the case of penicillin allergy evaluation and delabeling. The implementation, assessment, and refinement of advanced technologies, including clinical informatics and artificial intelligence, along with continued education of health care providers have potential to improve EHR documentation and communication, thereby advancing patient safety efforts.

A retrospective, 5-year, clinicoepidemiological study of severe cutaneous adverse reactions (SCARs)

BACKGROUND

A severe cutaneous adverse reaction (SCAR) is a rare, clinically heterogeneous, life-threatening phenomenon that results in serious skin damage, systemic complications, and significant morbidity or mortality comprising of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or SJS-TEN overlap, acute generalized exanthematous pustulosis (AGEP), exfoliative dermatitis, and drug rash with eosinophilia and systemic symptoms (DRESS).

MATERIALS AND METHODS

A retrospective study was conducted on all cases of SCARs admitted in a tertiary care referral hospital from January 2015 to December 2019. Clinical and epidemiological details were retrieved from the records of patients as per predesigned proforma. The data collected were analyzed and statistically evaluated.

RESULTS AND ANALYSIS

A total of 142 patients (67 males, 75 females) with SCARs, constituting 0.08% of total hospital admission and 0.027% of total dermatology outpatient department (OPD), were studied. Age group ranged from 2 to 61 years, with the mean age of 33.6 years (SD = 17.43). Most patients belonged to SJS-TEN complex (75 cases; SJS 48, SJS-TEN 18, TEN nine) followed by exfoliative dermatitis (27 cases/19%), AGEP (26 cases/18.3%), and DRESS (14 cases/9.8%). Anticonvulsants were most commonly implicated (22%) followed by antibiotics (20%), nonsteroidal anti-inflammatory drugs (NSAIDs) (17%), and ayurvedic (7%). There was only single mortality in a DRESS patient.

CONCLUSION

SCAR has considerable disease burden with marginal female preponderance in SJS/TEN and exfoliative dermatitis and can involve even the pediatric population. Anticonvulsants followed by antibiotics, NSAIDs, and ayurvedic medicines are common groups known to cause SCARs. To date, there are no definitive recommendations regarding their optimal treatment regimen, hence early diagnosis, prompt withdrawal of culprit drug, high standard of nursing care, and interdisciplinary consultations are vital steps to avoid disease progression and restore health.

Review on Databases and Bioinformatic Approaches on Pharmacogenomics of Adverse Drug Reactions

Pharmacogenomics has been used effectively in studying adverse drug reactions by determining the person-specific genetic factors associated with individual response to a drug. Current approaches have revealed the significant importance of sequencing technologies and sequence analysis strategies for interpreting the contribution of genetic variation in developing adverse reactions. Advance in next generation sequencing and platform brings new opportunities in validating the genetic candidates in certain reactions, and could be used to develop the preemptive tests to predict the outcome of the variation in a personal response to a drug. With the highly accumulated available data recently, the in silico approach with data analysis and modeling plays as other important alternatives which significantly support the final decisions in the transformation from research to clinical applications such as diagnosis and treatments for various types of adverse responses.

Prostate Cancer Radiotherapy: Increased Biochemical Control and Late Toxicity in Men With Medication Allergies

Background

Given similarities in the mediators of medication allergy (MA) and tissue response to radiotherapy, we assessed whether outcomes following prostate radiotherapy differ in patients with MAs.

Methods

A total 587 men with known MA history and nonmetastatic prostate cancer underwent radiotherapy from 1989 to 2006. Clinicopathologic and treatment variables were analyzed for association with freedom from biochemical failure (FFBF) and late treatment–related, physician-defined Radiation Therapy Oncology Group gastrointestinal (GI) and genitourinary (GU) toxicity. Covariates identified on univariate analysis for toxicity and disease control were examined on multivariable analysis. All statistical tests were 2-sided, and a P less than .05 was considered statistically significant.

Results

A total of 155 of 587 men (26.4%) had 1 or more MAs, most commonly to penicillin (n = 71), sulfa (n = 35), and aspirin or nonsteroidal antiinflammatory drugs (n = 28). On univariate analysis, men with MAs had superior 10-y FFBF (71.5% vs 63.5%, P = .02) and higher incidence of late GI grade 2 or higher (G2+; 20.6% vs 13.2%, P = .04) and grade 3 or higher (G3+; 7.5% vs 3.9%, P = .08) as well as late GU G2+ (42.5% vs 33.2%, P = .04) and G3+ (7.5% vs 3.0%, P = .02) toxicity than men without MAs. On multivariable analysis, MA history remained a statistically significant predictor of FFBF (hazard ratio [HR] = 0.64, 95% confidence interval [CI] = 0.43 to 0.93, P = .02), late G2+ GI (HR = 1.76, 95% CI = 1.06 to 2.90, P=.03), and G3+ GU (HR = 2.69, 95% CI = 1.16 to 6.27, P = .02) toxicity after controlling for corresponding covariates in each model.

Conclusions

Men with MAs had improved FFBF and increased treatment-related toxicity following radiotherapy for prostate cancer. MA history could be a relevant consideration in the management of men with localized prostate cancer.

Pharmacogenomics for Primary Care: An Overview

Most of the prescribing and dispensing of medicines happens in primary care. Pharmacogenomics (PGx) is the study and clinical application of the role of genetic variation on drug response. Mounting evidence suggests PGx can improve the safety and/or efficacy of several medications commonly prescribed in primary care. However, implementation of PGx has generally been limited to a relatively few academic hospital centres, with little adoption in primary care. Despite this, many primary healthcare providers are optimistic about the role of PGx in their future practice. The increasing prevalence of direct-to-consumer genetic testing and primary care PGx studies herald the plausible gradual introduction of PGx into primary care and highlight the changes needed for optimal translation. In this article, the potential utility of PGx in primary care will be explored and on-going barriers to implementation discussed. The evidence base of several drug-gene pairs relevant to primary care will be outlined with a focus on antidepressants, codeine and tramadol, statins, clopidogrel, warfarin, metoprolol and allopurinol. This review is intended to provide both a general introduction to PGx with a more in-depth overview of elements relevant to primary care.

Maternal known drug allergy and long-term dermatological morbidity of the offspring

Drug allergy is associated with adverse short-term perinatal outcomes such as caesarian delivery and preterm delivery. The aim of the present study was to determine whether being born to a mother with known drug allergy increases the risk for long-term dermatological morbidity of the offspring. A population-based cohort study, comparing long-term dermatological morbidity of offspring to mothers with and without known drug allergy, was conducted. Dermatological morbidity was assessed up to the age of 18 years according to a predefined set of ICD-9 codes associated with hospitalization of the offspring. A Kaplan-Meier survival curve was used to compare cumulative incidence of long-term dermatological morbidity, and a Cox proportional hazards model was constructed to control of confounders. During the study period, 243,682 deliveries met the inclusion criteria, of them 4% (n = 9756) were of mothers with known drug allergy. Offspring born to mothers with known drug allergy had higher rates of long-term dermatological morbidity Likewise, the cumulative incidence of long-term dermatological morbidity was higher as compared with those without known drug allergy (Kaplan-Meier log-rank P = .021). Using a Cox proportional hazards model, controlling for confounders, being born to a mother with known drug allergy was found to be an independent risk factor for long-term dermatological morbidity of the offspring (adjusted HR 1.2, 95% CI 1.03-1.33, P = .016). Being born to a mother with known drug allergy is independently associated with higher risk for long-term dermatological morbidity of the offspring.

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.

Impact of reported NSAID "allergies" on opioid use disorder in back pain

BACKGROUND

It is crucial to identify patients at highest risk for opioid use disorder (OUD) and to address challenges in reducing opioid use. Reported nonsteroidal anti-inflammatory drug (NSAID) allergies may predispose to use of stronger pain medications and potentially to OUD.

OBJECTIVE

We sought to investigate the clinical impact of reported NSAID allergy on OUD in patients with chronic back pain.

METHODS

We conducted a retrospective study of adults receiving care at a tertiary health care system from January 1, 2013, to December 31, 2018. Back pain and OUD were identified using administrative data algorithms. We used propensity score matching and logistic regression to estimate the impact of self-reported NSAID adverse drug reactions (ADRs) on risk of OUD, adjusting for other relevant clinical information.

RESULTS

Of 47,114 patients with chronic back pain, 3,620 (7.7%) had a reported NSAID ADR. In an adjusted propensity score-matched analysis, patients with NSAID ADRs had higher odds (odds ratio, 1.34; 95% CI, 1.07-1.67) of developing OUD as compared with those without NSAID ADRs. Additional risk factors for OUD included younger age, male sex, Medicaid insurance, Medicare insurance, higher number of inpatient and outpatient visits in the previous year, and comorbid anxiety and depression. Patients with listed NSAID ADRs also had higher odds of a documented opioid prescription during the study period (odds ratio, 1.22; 95% CI, 1.11-1.34).

CONCLUSIONS

Adults with chronic back pain and reported NSAID ADRs are at a higher risk of developing OUD and receiving opioid analgesics, even after accounting for comorbidities and health care utilization. Allergy evaluation is critical for potential delabeling of patients with reported NSAID allergies and chronic pain.

Residents and interns in the 3 university hospitals: their knowledge of and attitudes to drug allergy

Background

Previous studies revealed there are many gaps in the awareness and knowledge regarding the diagnosis and management of drug allergy (DA) among various health-care professionals.

Objective

To assess the knowledge, attitudes, and practices towards DA among residents and interns of 3 university hospitals in the region of Trakya (Thrace), Turkey.

Methods

A cross-sectional survey was conducted at university hospitals of 3 cities in the Trakya region: 1. Trakya University Medical Faculty, Edirne (n = 405), 2. Namik Kemal University Medical Faculty, Tekirdag (n = 114), and 3. Canakkale 18 Mart University Medical Faculty, Canakkale (n = 111). A Turkish questionnaire was developed based on previous published studies.

Results

The majority of participants (67%) had not received education on DA as a separate subject during their medical education. Less than a third (28.3%) of all respondents were satisfied with their knowledge concerning patients with clinical signs of DA. Of the 6 knowledge questions on DA, the average score for the study was 3.51 out of 6 (58.5%). Residents had a higher knowledge score (3.93 ± 1.1) compared with interns (3.05 ± 1.2) (p < 0.001). The lowest percentage of correct answers were in response to questions on laboratory confirmation of drug-related anaphylaxis (14.5%) and the possibility of penicillin toleration in patients with a history of penicillin allergy (11.8%). The majority of participants (92%) believe that medical doctors should be educated in DA. There were no significant correlations between taking DA histories and the frequency during daily practice of encountering patients.

Conclusion

Our study revealed that DA knowledge and attitudes are not at satisfactory level among respondents, and we concluded the importance and necessity of reinforcement of DA education in pre- and postgraduate education of medical doctors.

In vitro identification of drugs inducing systemic hypersensitivity reactions known in vivo to be associated with specific HLA genotypes

Hypersensitivity drug reactions (HDRs) are common among drugs, despite this, there are no validated in vitro or in vivo methods for screening the sensitizing potential of drugs in the preclinical phase. We previously developed the THP-1 activation assay, based on CD86 upregulation and IL-8 production, for the in vitro identification of drugs able to induce selective dendritic cell activation. In this paper, we investigated the predictive capacity of the method toward drugs associated with HDRs for which a correlation with specific human leukocyte antigens (HLA) have been demonstrated. For that purpose, abacavir, carbamazepine and clozapine were used. Metformin was used as negative control. Dose- and time-course experiments were conducted. The surface markers CD86, CD54 and HLA-DR were evaluated by flow cytometry analysis, whereas IL-8 release by ELISA. Abacavir, carbamazepine and clozapine gave positive results with CD86 upregulation and/or IL-8 release, with abacavir also inducing HLA-DR. The test reveals the ability of drugs to induce dendritic cell activation (signals 1/2), that preceded the adaptive immune response, which will be manifested only in a minority of patients carrying the specific HLA genotypes. The idea is to integrate this simple method during drug development to identify the potential of drugs to induce hypersensitivity reactions in the pre-clinical phase.

Hypersensitivity reactions to non-steroidal anti-inflammatory drugs: results of an Austrian cohort study

Background

Hypersensitivity to non-steroidal anti-inflammatory drugs (NSAIDs) is the second most common cause of drug hypersensitivity. Despite the importance of NSAIDs in routine analgesia only few studies have systematically addressed the question of tolerability in hypersensitive patients.

Methods

The authors retrospectively analysed 398 patients that were treated at the Department of Dermatology, Kepler University Hospital Linz, Austria, in the period 2012–2016 with a clinical history of NSAID hypersensitivity. Skin tests (skin prick and intracutaneous tests) to common NSAIDs were performed, followed by single-blinded, placebo-controlled drug challenge with either the culprit drug or an alternative NSAID.

Results

A total of 361 patients were subjected to skin testing. Of these, 25 patients (6.3%) showed a positive reaction to the culprit drug. According to the severity of the reaction in the medical history, 87 patients were exposed orally to the culprit drug (oral provocation test, OPT) after negative skin test and 255 patients received OPT with alternative NSAIDs according to established protocols. OPT with the culprit drug resulted in hypersensitivity reactions in 12 patients (13.79%). In terms of alternative NSAID testing, the three most commonly tested drugs were lornoxicam (192 OPTs), acetaminophen (156 OPTs) and celecoxib (133 OPTs) with tolerability rates in respectively 88.54% (hypersensitivity reactions, 11.46%), 92.31% (hypersensitivity reactions, 7.69%) and 91.73% (hypersensitivity reactions, 8.27%) of cases.

Conclusion

OPT with alternative NSAIDs are useful in patients with NSAID hypersensitivity as tolerability varies between the individual substances.

A Survey on Knowledge Gaps in Assessment and Management of Severe Drug Hypersensitivity Reactions: Multicenter Cross-Sectional Study of Australian Health Care Providers

Severe drug hypersensitivity reactions (DHRs) are often encountered by health care professionals (HCPs). We evaluated knowledge of doctors and pharmacists in the assessment and management of severe DHRs using a structured questionnaire. A cross-sectional study was conducted in 4 metropolitan hospital networks in Melbourne, Australia. A 13-question, scenario-based multiple-choice questionnaire to assess specific knowledge domains in drug hypersensitivity syndrome recognition, causality attribution, cross-reactivity patterns, appropriate diagnostic tests, and therapy was administered to HCPs of various vocation and specialty groups. Data were analyzed according to profession, self-reported experience, and preparedness in managing severe DHRs. Two hundred thirty-eight participants (45.0% senior doctors, 24.4% junior doctors, and 30.7% pharmacists) across a range of subspecialties achieved an overall median score of 7 (IQR, 5-8)-overall 55.6% correct responses to all questions-with senior doctors outperforming junior doctors and pharmacists (P < .001). The best performance by all participants was in DHR syndrome recognition (60.9%), and the poorest was in diagnostics/therapy (52.0%). HCP group and experience level were significantly associated with better performance in the knowledge domains of cross-reactivity and diagnostics/therapy (P = .003 and < .001, respectively), but not in the domains of syndrome recognition and causality attribution (P > .05). Levels of self-reported preparedness in DHR management were not associated with performance rates in any of the knowledge domains. This study demonstrated significant knowledge gaps in the recognition and management of severe drug hypersensitivity reactions. Targeted multidisciplinary education of staff caring for these patients is needed to improve knowledge gaps.

Cutaneous drug eruptions including serum sickness-like reaction, symmetrical drug-related intertriginous and flexural exanthema, and drug-induced lupus

Cutaneous manifestations of drug reactions are common yet vary widely in their appearance and degree of internal organ involvement. Serum sickness--like reactions, symmetrical drug-related intertriginous and flexural exanthem, granulomatous drug eruption, pseudolymphoma, and drug-induced lupus are medication-induced conditions with dermatologic presentations. Many of the conditions discussed are relatively rare but nonetheless demand our attention and understanding. Some of the conditions presented may be more likely encountered in the hospital setting, as is the case with serum sickness-like reactions and drug-induced lupus, whereas others may present to outpatient clinic for diagnosis. Given the similarities in clinical history of patients presenting with these conditions, an understanding of the clinical presentation, pathophysiology, culprit medications, histologic appearance, and serologic characteristics is warranted to correctly diagnose and manage these uncommon adverse reactions. We also discuss how to differentiate some of these conditions from more serious mimickers, as in the case of pseudolymphoma drug reaction mimicking a true lymphoma and drug-induced lupus mimicking acute systemic lupus erythematosus.