Drug allergy awareness and perspectives with the implementation of the International Classification of Diseases-11.

PURPOSE OF REVIEW: To understand the current global scale of drug hypersensitivity (DH) and drug allergy (DA), and to identify possible strategies to increase the accuracy of epidemiological data. RECENT FINDINGS: Global patterns of DH/DA seem to be changing and increasing worldwide, but there are still great challenges in capturing quality DH/DA mortality and morbidity statistics (MMS). DH/DA MMS may gain new perspectives with the global implementation of the International Classification of Diseases (ICD)-11. Improving the quality of epidemiological data related to DH/DA should clarify areas of uncertainty, which would lead to better strategies to reduce the burden of these conditions. SUMMARY: DH/DA remains a complex and unaddressed problem globally that often deprives patients of optimal medication choices and places them at risk for life-threatening reactions. DH/DA labels should contribute to people well being, by protecting true allergic individuals from being re-exposed to their allergic drugs and providing needed medications to individuals wrongly labeled as allergic or who have lost allergic sensitivity. The true rate of DH/DA is in fact unknown due to a number of factors, such as misdiagnosis, miscoding and under- and over-notification, among others. Moreover, there is lack of data about DH/DA epidemiology in many countries. Difficulties on collecting accurate and comparable data should be acknowledged, with great impact in the correct labeling DH/DA in electronic health records and official statistics. More accurate definitions, classification and coding may contribute to a better-quality MMS thanks to the ICD-11, under implementation worldwide. Improving the quality of epidemiological data related to DH/DA should clarify areas of uncertainty, which would lead to better strategies to reduce the burden of these conditions. As knowledge derived from populations is key information for more realistic decision-making, the construction of the new section addressed to DH/DA in the ICD-11 will allow the collection of more accurate epidemiological data to support quality management of patients, and facilitate healthcare planning to implement public health measures to prevent and reduce the morbidity and mortality attributable to these conditions.

Improving the performance of machine learning penicillin adverse drug reaction classification with synthetic data and transfer learning.

BACKGROUND: Machine learning may assist with the identification of potentially inappropriate penicillin allergy labels. Strategies to improve the performance of existing models for this task include the use of additional training data, synthetic data and transfer learning. AIMS: The aims of this study were to investigate the use of additional training data and novel machine learning strategies, namely synthetic data and transfer learning, to improve the performance of penicillin adverse drug reaction (ADR) machine learning classification. METHODS: Machine learning natural language processing was applied to free-text penicillin ADR data extracted from a public health system electronic health record (EHR). The models were developed by training on various labelled data sets. ADR entries were split into training and testing data sets and used to develop and test a variety of machine learning models. The effect of training on additional data and synthetic data versus the use of transfer learning was analysed. RESULTS: Following the application of these techniques, the area under the receiver operator curve of best-performing models for the classification of penicillin allergy (vs intolerance) and high-risk allergy (vs low-risk allergy) improved to 0.984 (using the artificial neural network model) and 0.995 (with the transfer learning approach) respectively. CONCLUSIONS: Machine learning models demonstrate high levels of accuracy in the classification and risk stratification of penicillin ADR labels using the reaction documented in the EHR. The model can be further optimised by incorporating additional training data and using transfer learning. Practical applications include automating case detection for penicillin allergy delabelling programmes.

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 (AU)

Symptoms Associated with Gadolinium Exposure (SAGE): A Suggested Term.

In this article, members of the American College of Radiology Committee on Drugs and Contrast Media propose a new term for symptoms reported after intravascular exposure to gadolinium-based contrast agents-Symptoms Associated with Gadolinium Exposure, or SAGE. This term is advocated in lieu of other proposed nomenclature that presumes a causal relationship that has not yet been scientifically verified. The purpose of this new term, SAGE, is to assist researchers and clinical providers in describing such symptoms without prematurely causally attributing them to a disease and to standardize reporting of these symptoms to allow for coherent interpretation of related studies.

Hypersensitivity to Vitamins with a Focus on Immediate-Type Reactions: Food or Drug Allergy?

Vitamins are essential substances for normal cell functions, growth, and development. However, they cannot be produced by the human organism, so intake must be through the diet. Vitamin deficiency causes the onset of different diseases, ranging from pellagra to pernicious anemia, which can be corrected by reintroducing the missing vitamin form. To supply the right amount of vitamins to the body, every vitamin naturally occurring in foodstuff has been identified, extracted and synthetically produced, thus allowing either food fortification with these compounds or their pharmaceutical production. Furthermore, the increased importance attributed nowadays to body wellness and the pursuit of a permanent status of health at all costs has greatly encouraged a high consumption of vitamin supplements in modern society, since vitamin megadoses may be responsible for adverse or toxic effects. However, excessive vitamins can induce hypervitaminosis. In the USA, a national survey confirmed that 52% of adult Americans take at least one or more supplement products, vitamins and minerals being the most popular supplements in that country. Although vitamins are widespread natural substances, they may induce immediate or delayed type hypersensitivity reactions. Such adverse events are still underestimated and poorly recognized because only single cases have been reported in the literature, and no general review has yet investigated the mechanisms underlying sensitization to each vitamin, the diagnosis, and the management strategies adopted for vitamin hypersensitivity. Although delayed-type reactions to different vitamins are described in the literature, in our review, attention has been focused mainly on immediate- type reactions. Due to the importance of vitamins, further information regarding the above aspects (pathomechanisms, diagnosis and management) would be highly desirable to focus the state of the art on this particular, underestimated form of allergy, thus increasing allergists' awareness on these elusive hypersensitivity reactions.

Categorization of adverse drug reactions in electronic health records.

The purpose of this study was to evaluate the quality of adverse drug reaction (ADR) documentation in a state-wide electronic health record (EHR), and to assess the impact of the interface design on documentation accuracy and ability to provide decision support. Data were extracted from 43 011 unique records in a state-wide electronic health record in South Australia, Australia. Information obtained included ADR coding as allergy or intolerance, allergen name, reaction, and occupation of those entering data. Categorization into drug allergy or intolerance was assessed for accuracy. Reactions were entered predominantly by nurses (60.1%), also by doctors (31.0%) and pharmacists (6.1%). Of 27 314 reactions, 86.5% were coded as allergy and 13.5% as intolerance. The majority (78.2%) described reactions to drugs (as opposed to food, environmental or contact allergens), predominantly chosen from the drug database (96.4%). Many entries used free text for the reaction description (27.4%). Terms found in the predefined list under the allergy heading were more likely to be categorized as allergy, even when the mechanism was pharmacological intolerance. Only 45.1% (n = 1671/3705) of reactions consistent with intolerance (eg, "nausea," "diarrhea") were correctly categorized as such, although categorization by pharmacists was more accurate (P < .0001). These data suggest that ADR categorization as allergy or intolerance is influenced by the EHR design. The obligatory classification of ADRs into allergy or intolerance was not well understood and does not appear to have practical benefit.

New Classification Schemata of Hypersensitivity Adverse Effects After Hyaluronic Acid Injections: Pathophysiology, Treatment Algorithm, and Prevention.

BACKGROUND: Side effects during hyaluronic acid (HA) injection are considered mild and reversible; however, an alarming trend of increased hypersensitivity reactions has recently been reported. OBJECTIVE: The goal of this article is to review the hypersensitivity reactions reported in the literature and, in combination with the authors' experience, to create a classification system to sort the timing and clinical manifestations of these reactions, as well as a treatment schema to manage their clinical course. METHODS: A literature search using PubMed, Ovid MEDLINE, and Embase databases was performed with no date restrictions. Search terms included "hyaluronic acid and hypersensitivity" and "hyaluronic acid and nodules." Data analyzed included study type, number of subjects, HA filler type, injection location, adverse reaction, timing, treatment, and outcomes. RESULTS: Thirty-six studies were identified, documenting hypersensitivity reactions to HA treatment. Twelve cases described events occurring within a week, 6 within a month, and 31 after a month of treatment. Combined with the authors' experience, a new classification system and management of hypersensitivity reactions to HA fillers is proposed of early (up to a week), intermediate (a week to a month), and late (over a month) hypersensitivity reactions. CONCLUSION: The classification system proposed provides objective measurements and management options that can be helpful for physicians to navigate these hypersensitivity reactions and design treatment protocols that provide the best clinical outcomes for their patients.

Update on the Management of Nonsteroidal Anti-Inflammatory Drug Hypersensitivity.

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

An educational intervention about the classification of penicillin allergies: effect on the appropriate choice of antibiotic therapy in pregnant women.

BACKGROUND: Most pregnant women who self-report penicillin allergy are not truly penicillin-allergic and this misunderstanding often leads to administration of inappropriate antibiotic therapy. Decision algorithms have been developed to guide antibiotic selection but major discrepancies have been reported between guidelines and clinical practice. We aimed to optimize the prescription of antibiotics for pregnant women who self-reported penicillin allergy, using an educational intervention about the classification of penicillin allergies that targeted gynecologists, anesthesiologists and midwives. METHODS: This quasi-experimental study assessed the effect of an educational intervention about the classification of penicillin allergy. For six months, a combination of two strategies was used, namely dissemination of printed educational materials and group education. The principal study endpoint was the appropriateness of the antibiotic therapy, defined in advance for each level of allergic risk. RESULTS: The pre-intervention phase included 903 women; one year after its conclusion, the post-intervention phase began and included 892 women. The prevalence of self-reported penicillin allergy was stable over the two periods (6.8% before vs 5.4% after, P=0.24). The clinical classification of penicillin allergies was more often used after the educational intervention (68% vs 100%, P<0.001). The appropriateness of the antibiotic therapy prescribed to self-reported penicillin allergic-women increased significantly between the two periods, from 5/29 (17.2%) to 18/27 (66.7%, P<0.001). CONCLUSION: An educational intervention about penicillin allergy classification was associated with an improvement in the choice of appropriate antibiotic therapy among women who had reported penicillin allergy.

Clinical Phenotypes of Severe Cutaneous Drug Hypersensitivity Reactions.

Drug hypersensitivity reactions are clinically heterogenous ranging from mild to severe. Most drug hypersensitivity reactions are accompanied by cutaneous manifestations. Fever, mucous membrane involvement, large blisters, facial oedema, pustulosis and visceral involvement are clinical features that lead to suspicion of severe adverse drug reactions. Severe cutaneous adverse drug reactions (SCARs) include Stevens-Johnson syndrome, toxic epidermal necrolysis, drug rash eosinophilia and systemic symptoms, acute generalized exanthematous pustulosis. Serum sickness like reactions, drug induced vasculitis and generalized bullous fixed drug eruptions are less severe clinical entities. SCARs are uncommon but associated with significant morbidity and mortality. Physician should be aware of specific red flags and danger signs to immediately identify these reactions. Immediate drug withdrawal is mandatory. Early diagnosis and appropriate treatment significantly affect the prognosis of the disease. The purpose of our review is to discuss clinical phenotypes of severe cutaneous drug hypersensitivity reactions.

Mechanisms of hypersensitivity reactions induced by drugs.

Adverse drug reactions include drug hypersensitivity reactions (DHRs), which can be immunologically mediated or non-immunologically mediated. The high number of DHRs unconfirmed and/or self-reported is a frequent problem in daily clinical practice, with considerable impact on future prescription choices and patient health. It is important to distinguish between hypersensitivity and non-hypersensitivity reactions by adopting a structured diagnostic approach to confirm or discard the suspected drug, not only to avoid life-threatening reactions, but also to reduce the frequent over-diagnosis of DHRs.

EAACI position paper on how to classify cutaneous manifestations of drug hypersensitivity.

Drug hypersensitivity reactions (DHRs) are common, and the skin is by far the most frequently involved organ with a broad spectrum of reaction types. The diagnosis of cutaneous DHRs (CDHR) may be difficult because of multiple differential diagnoses. A correct classification is important for the correct diagnosis and management. With these guidelines, we aim to give precise definitions and provide the background needed for doctors to correctly classify CDHR.

Identification of Inpatient Allergic Drug Reactions Using ICD-9-CM Codes.

BACKGROUND: The study of allergic drug reactions has been limited because of challenges in identifying and confirming cases. OBJECTIVE: To determine the utility of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for identifying inpatient allergic drug reactions and to compare findings with previous data in the emergency department. METHODS: By reviewing medical records of inpatients with ICD-9-CM codes and E codes suggestive of allergic drug reactions at a large urban academic medical center, we determined codes that yielded the most drug allergy cases and identified culprit drugs. RESULTS: In 2005 and 2010, 3337 and 5282 possible allergic drug reactions during hospitalization were identified and 1367 were reviewed. Allergic drug reactions were found in 409 (30.1%) of the reviewed charts, with 172 (29.7%) in 2005 and 237 (30.5%) in 2010. The codes that identified the highest percentage of true allergic drug reactions were dermatitis due to drug (693.0), allergic urticaria (708), angioneurotic edema (995.1), and anaphylaxis (995.0). Antibiotics were the most common cause (44.4%); however, multiple drug classes were often identified as likely culprit drugs. CONCLUSION: Specific ICD-9-CM codes can identify patients with allergic drug reactions, with antibiotics accounting for almost half of true reactions. Most patients with codes 693.0, 995.1, 708, and 995.0 had allergic drug reactions, with 693.0 as the highest yield code. An aggregate of multiple specific codes consistently identifies a cohort of patients with confirmed allergic drug reactions.

Antibiotic allergy.

Antibiotics are the commonest cause of life-threatening immune-mediated drug reactions that are considered off-target, including anaphylaxis, and organ-specific and severe cutaneous adverse reactions. However, many antibiotic reactions documented as allergies were unknown or not remembered by the patient, cutaneous reactions unrelated to drug hypersensitivity, drug-infection interactions, or drug intolerances. Although such reactions pose negligible risk to patients, they currently represent a global threat to public health. Antibiotic allergy labels result in displacement of first-line therapies for antibiotic prophylaxis and treatment. A penicillin allergy label, in particular, is associated with increased use of broad-spectrum and non-ß-lactam antibiotics, which results in increased adverse events and antibiotic resistance. Most patients labelled as allergic to penicillins are not allergic when appropriately stratified for risk, tested, and re-challenged. Given the public health importance of penicillin allergy, this Review provides a global update on antibiotic allergy epidemiology, classification, mechanisms, and management.

Allergic-like contrast media reaction management in children.

The use of contrast materials as part of imaging examinations is common in children of all ages, as these compounds increase image contrast, lesion detection and lesion characterization. Though modern iodinated, gadolinium-based and ultrasound microbubble contrast materials generally are quite safe, acute physiological and allergic-like reactions are possible. The majority of acute contrast reactions in children are mild and self-limited; however, life-threatening reactions can occur. It is our obligation as radiologists to recognize and manage these adverse reactions. The objective of this article is to review the frequency, manifestations and appropriate treatment of acute contrast reactions in the pediatric population.

Drug Hypersensitivity.

BACKGROUND: Adverse drug reactions (ADRs) can be divided into pharmacological ADRs (type A) and hypersensitivity reactions (type B). Type B reactions can be further subdivided into immediate (<1 h, urticaria, anaphylaxis) and delayed reactions (>1 h, variable manifestation like exanthema, hepatitis, cytopenias). Prevention of hypersensitivity is often still a challenge. METHODS: Selective literature search in Medline and Google Scholar as well as research in ADR databases like OpenVigil or SIDER. RESULTS: Laboratory tests ([specific] IgE, lymphocyte transformation test), histological examination, dermatological tests (prick tests, epicutaneous testing) and-under certain circumstances-provocation tests can be used for diagnostics. There are only a few pharmacogenetic biomarkers to predict hypersensitivity reactions. Currently, testing for defined HLA genes is mandatory before prescription of abacavir and before the use of carbamazepine in Han Chinese or Thai patients. Immediate discontinuation of the trigger is essential in all allergic hypersensitivity reactions. Immediate reactions are treated with antihistamines, glucocorticoids and occasionally with epinephrine. Delayed reactions are usually treated with glucocorticoids. CONCLUSION: Careful, structured diagnostics in case of suspected hypersensitivity together with adequate documentation (allergy passport) is necessary in order to avoid incidents in patients receiving subsequent treatment. Consistent use of existing resources (diagnostics and documentation) can help to avoid hypersensitivity reactions or to rapidly recognize and treat them, respectively.

Antibiotic Allergy in Pediatrics.

The overlabeling of pediatric antibiotic allergy represents a huge burden in society. Given that up to 10% of the US population is labeled as penicillin allergic, it can be estimated that at least 5 million children in this country are labeled with penicillin allergy. We now understand that most of the cutaneous symptoms that are interpreted as drug allergy are likely viral induced or due to a drug-virus interaction, and they usually do not represent a long-lasting, drug-specific, adaptive immune response to the antibiotic that a child received. Because most antibiotic allergy labels acquired in childhood are carried into adulthood, the overlabeling of antibiotic allergy is a liability that leads to unnecessary long-term health care risks, costs, and antibiotic resistance. Fortunately, awareness of this growing burden is increasing and leading to more emphasis on antibiotic allergy delabeling strategies in the adult population. There is growing literature that is used to support the safe and efficacious use of tools such as skin testing and drug challenge to evaluate and manage children with antibiotic allergy labels. In addition, there is an increasing understanding of antibiotic reactivity within classes and side-chain reactions. In summary, a better overall understanding of the current tools available for the diagnosis and management of adverse drug reactions is likely to change how pediatric primary care providers evaluate and treat patients with such diagnoses and prevent the unnecessary avoidance of antibiotics, particularly penicillins.

Hypersensitivity reactions to therapeutic monoclonal antibodies: Phenotypes and endotypes.

BACKGROUND: The increasing use of mAbs has led to a rise in hypersensitivity reactions (HSRs), which prevent their use as first-line therapy. HSRs' symptoms, diagnostic tools, and directed management approaches have not been standardized. OBJECTIVE: We propose a novel evidence-based classification of HSRs to mAbs, based on the clinical phenotypes, underlying endotypes and biomarkers, as well as their management with desensitization. METHODS: Phenotypes, endotypes, and biomarkers of HSRs to 16 mAbs for 104 patients were described and compared with the outcomes of 526 subcutaneous and intravenous desensitizations. RESULTS: Initial reactions presented with 4 patterns: type I-like reactions (63%), cytokine-release reactions (13%), mixed reactions (21%), and delayed type IV reactions (3%). In contrast, of the 23% breakthrough HSRs during desensitization, 52% were cytokine-release reactions, 32% were type 1, 12% were mixed, and 4% were type I with delayed type IV. Skin testing to 10 mAbs in 58 patients was positive in 41% of patients. Serum tryptase was elevated in 1 patient and IL-6 was elevated in 8 patients during desensitization and was associated with a cytokine-release phenotype. CONCLUSIONS: HSRs to mAbs can be defined as type I, cytokine-release, mixed (type I/cytokine-release), and type IV reactions, which are identified by biomarkers such as skin test, tryptase, and IL-6. These phenotypes can be used to improve personalized and precision medicine when diagnosing HSRs to mAbs and providing management recommendations with desensitization. Desensitization provides a safe and effective retreatment option to remain on culprit mAbs as first-line therapy.