Pro and Contra: Provocation Tests in Drug Hypersensitivity

Drugs and the skin: A concise review of cutaneous adverse drug reactions

Drug-induced skin disease or cutaneous adverse drug reactions (CADRs) are terms that encompass the clinical manifestations of the skin, mucosae and adnexa induced by a drug or its metabolites. The skin is the organ most frequently affected by drug reactions, which may affect up to 10% of hospitalized patients and occur in 1-3% of multimedicated patients. Most CADRs are mild or self-resolving conditions; however, 2-6.7% of could develop into potentially life-threatening conditions. CADRs represent a heterogeneous field and can be diagnostically challenging as they may potentially mimic any dermatosis. Currently, there are between 29-35 different cutaneous drug-reaction patterns reported ranging from mild dermatitis to an extensively burnt patient. The most frequently reported are maculopapular rash, urticaria/angioedema, fixed drug eruption and erythema multiforme. Less common but more severe patterns include erythroderma, drug reaction with eosinophilia and systemic symptoms, and Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum. Almost any drug can induce a CADR, but antibiotics, nonsteroidal anti-inflammatory drugs and antiepileptics are the most frequently involved. Different mechanisms are involved in the pathogenesis of CADRs, although in some cases, these remain still unknown. CADRs could be classified in different ways: (i) type A (augmented) or type B (bizarre); (ii) immediate or delayed; (iii) immune-mediated or nonimmune-mediated; (iv) nonsevere or life-threatening; and (v) by their phenotype, including exanthematous, urticarial, pustular and blistering morphology. Recognizing a specific CADR will mostly depend on the ability of the physician to perform a detailed clinical examination, the proper description of the morphology of the skin lesions and supporting laboratory and/or skin biopsy findings.

The Application of Knowledge-Based Clinical Decision Support Systems to Detect Antibiotic Allergy

Prevention of drug allergies is important for patient safety. The objective of this study was to evaluate the outcomes of antibiotic allergy-checking clinical decision support system (CDSS), K-CDSTM. A retrospective chart review study was performed in 29 hospitals and antibiotic allergy alerts data were collected from May to August 2022. A total of 15,535 allergy alert cases from 1586 patients were reviewed. The most frequently prescribed antibiotics were cephalosporins (48.5%), and there were more alerts of potential cross-reactivity between beta-lactam antibiotics than between antibiotics with the same ingredients or of the same class. Regarding allergy symptoms, dermatological disorders were the most common (38.8%), followed by gastrointestinal disorders (28.4%). The 714 cases (4.5%) of immune system disorders included 222 cases of anaphylaxis and 61 cases of severe cutaneous adverse reactions. Alerts for severe symptoms were reported in 6.4% of all cases. This study confirmed that K-CDS can effectively detect antibiotic allergies and prevent the prescription of potentially allergy-causing antibiotics among patients with a history of antibiotic allergies. If K-CDS is expanded to medical institutions nationwide in the future, it can prevent an increase in allergy recurrence related to drug prescriptions through cloud-based allergy detection CDSSs.

EAACI/ENDA position paper on drug provocation testing

In drug hypersensitivity, drug provocation testing (DPT), also called drug challenge, is the gold standard for investigation. In recent years, risk stratification has become an important tool for adjusting the diagnostic strategy to the perceived risk, whilst still maintaining a high level of safety for the patient. Skin tests are recommended before DPT but may be omitted in low-risk patients. The task force suggests a strict definition of such low-risk patients in children and adults. Based on experience and evidence from studies of allergy to beta-lactam antibiotics, an algorithm on how to adjust DPT to the risk, and when to omit skin tests before DPT, is presented. For other antibiotics, non-steroidal anti-inflammatory drugs and other drugs, skin tests are poorly validated and DPT is frequently necessary. We recommend performing DPT with chemotherapeutics and biologicals to avoid unnecessary desensitization procedures and DPT with skin tests negative contrast media. We suggest DPT with anesthetics only in highly specialized centers. Specifics of DPT to proton pump inhibitors, anticonvulsants and corticosteroids are discussed. This position paper provides general recommendations and guidance on optimizing use of DPT, whilst balancing benefits with patient safety and optimizing the use of the limited available resources.

[Reproducibilidad clínica de reacciones de hipersensibilidad a fármacos en pruebas de exposición controlada]

Objective

To assess the reproducibility of symptoms in drug challenge tests.

Methods

The study included patients with positive cutaneous or challenge test throughout 2019. For each patient, clinical suspicion according to Karch-Lasagna algorithm was registered. Primary outcome was the reproducibility of symptoms in the provocation tests using a paired analysis of data with McNemar test.

Results

Eighty-nine patients were included, 16 of them presented more than one positive test. Thirty were skin tests positive and 75 reacted to provocation tests. Eighty nine percent of patients who reacted in challenge test were probably or possibly reactors according to Karch-Lasagna scale. Symptoms of initial reaction did not differ from those triggered in challenge tests.

Conclusions

Karch-Lasagna scale is useful in predicting the response to drug provocation tests. In most of the positive studies, results were suggested by clinical history and no differences were found between symptoms triggered in challenge test and that referred to in the previous reaction.

Drug provocation tests in children: All that glitters is not gold

A proper allergy work-up, based on the gold standard drug provocation test (DPT), usually rules out suspected drug hypersensitivity in children. These tests are generally open, given their high efficiency compared with double-blind placebo-controlled DPTs. Although their negative predictive value is excellent, no studies have calculated their positive predictive value, highly dependent on the prevalence of the disease. Most studies have found a rate of <5%-10% of true beta-lactam hypersensitivity in children. Given this low prevalence (pre-test probability), a few false-positive results can significantly reduce the estimated positive predictive value. False positives may arise from the nocebo effect during the test, including nocebo by proxy, or from observer bias, which depends on professional expertise and organizational circumstances. Some studies have found a high rate of tolerance on a second DPT in children who failed the first, but these results may be affected by the interval between the two tests, of a year or more in most cases, reflecting a loss of hypersensitivity over time. Taking into account the low rate of positive DPTs, with commonly mild reactions, we suggest confirming nonsevere positive DPTs with a second provocation performed soon after the first, especially in the case of beta-lactam antibiotics, in order to improve the diagnostic accuracy, de-label more patients, and achieve a better estimation of true drug hypersensitivity prevalence. In case of mild immediate reactions, the potential benefits of a second DPT should be carefully weighed against the risk of anaphylaxis.

Nanoparticulate impurities in the pharmaceutical excipient trehalose induce an early immune response

BACKGROUND

Pharmaceutical excipients are an important part of biological products. However, few attempts have been made to distinguish between the risk of inflammation associated with the biological products themselves and that associated with excipients. The analysis of early immune response risk associated with excipients added to biological products is an important step in exploring the complex mechanism of side effects in susceptible patients.

METHODS AND RESULTS

In this study, nanoparticle impurities (NPIs) were extracted from trehalose and characterized. A mouse popliteal lymph node cell (PLNA) model, a mouse spleen lymphocyte model, a human peripheral blood mononuclear cell cytokine release model, and a macrophage complement activation model were established to comprehensively evaluate the early immune risk related to impurities in the trehalose excipient. Although popliteal lymph node cell counts in mice did not show significant differences, all other models indicated possible immune risk. In the PLNA model, NPIs caused significant toe thickening in mice, whereby the content of IgE and MCP-1 increased significantly. NPIs significantly increased the proliferation and differentiation of spleen lymphocytes according to the CCK-8 assay and flow cytometry. After treatment with NPIs, the release of IgE and a variety of cytokines (MIP-1α, IFN-γ, IL-2, IL-8, TNF-α, IL-6, IL-1α) in human peripheral blood cells was significantly increased according to ELISA, while a concomitant increase of C3a/C5a as well as C4a/Bb proved that NPIs activated the complement system.

CONCLUSION

NPIs from trehalose elicited an immune response in vitro, and the immune response to trehalose may be related to NPIs and not the excipient itself. Different batches of trehalose showed different immune response effects. The currents research suggests that when trehalose is applied in high-risk administration routes, NPIs should be assessed and reasonably controlled.

Allergy in Cancer Care: Antineoplastic Therapy-Induced Hypersensitivity Reactions

As the backbone of oncological treatments, systemic chemotherapy is still one of the main pawns in cancer care, alone or in combination with newer targeted agents. All chemotherapy agents can be associated with a type of adverse event called an infusion reaction, which can be characterized as unpredictable, non-dose related, and unexplained by the cytotoxic profile of the drug. For some of these events, a certain immunological mechanism can be identified by blood or skin testing. In this case, we can speak of true hypersensitivity reactions that occur as a response to an antigen/allergen. The current work summarizes the main antineoplastic therapy agents and their susceptibility to induce hypersensitivity reactions and also includes a review of clinical presentation, diagnostic methods in hypersensitivity reactions, and perspectives to overcome these negative events in the treatment of patients suffering from various types of cancer.

A multidisciplinary approach to verify and de-label of drug allergic histories in a university hospital in Thailand: a retrospective descriptive study

BACKGROUND

Mislabeling of drug allergic histories causes avoidable negative impacts on patients and healthcare system. Although multidisciplinary adverse drug reaction (ADR) services to verify and de-label drug allergic histories have been operated in particular hospitals in Thailand, their performances have not been reported. This research aimed to examine the effectiveness of verification of drug allergic history and de-labeling (VD) services of the physician-led multidisciplinary ADR clinic.

METHODS

This research was a retrospective descriptive study. Medical charts of patients with at least one drug allergic history who received VD services at the multidisciplinary clinic between January 2017 to December 2018, were reviewed. Data on the history of drug allergy, VD services, and results were analyzed and presented using descriptive statistics.

RESULTS

Seventy patients' charts were reviewed, and 171 unconfirmed drug allergic histories were identified. 79.53% of the reported reactions involved skin and soft tissues. The most found adverse skin reactions were maculopapular rash, pruritic and erythematous rash, and angioedema. The remaining 20.47% were systemic reactions which included drug reaction with eosinophilia and systemic symptoms (DRESS), anaphylaxis, and nausea/vomiting was the most prevalent. Antituberculosis, beta-lactam antibiotics, and nonsteroidal anti-inflammatory drugs (NSAIDs) were the most reported suspected drugs. Drug allergic history reviewing by physicians or pharmacists could confirm and de-label for 3 and 20 reactions, respectively. Seven and one reactions were confirmed by enzyme-linked immunospot assay and patch test, respectively. The provocation tests with the suspected or alternative drug were conducted in 64 reactions. Twelve reactions were confirmed, and 45 reactions were de-labeled. Totally, 65/171 (38.01%) allergic histories were successfully de-labeled, 23/171 (13.45%) were confirmed, and 83/171 (48.53%) were inconclusive.

CONCLUSIONS

More than half of drug allergic histories were successfully confirmed or de-labeled by the multidisciplinary ADR team. The collaborative activities of various healthcare professionals, consisting of physicians, nurse, and pharmacists as presented in the study were effective in VD services and should be implemented in other healthcare settings.

Cofactors of drug hypersensitivity-A monocenter retrospective analysis

Background

Drug hypersensitivity reactions (DHRs) are major medical problems that influence the treatment of patients by both under- and overdiagnosis. Still, little is known about the role of predisposing or protecting cofactors of DHR.

Objective

This study aims to determine drug-specific cofactors in patients with DHR.

Methods

Retrospective file chart analysis of inpatients with suspected DHR in our department between 2015 and 2020 was performed. Descriptive statistics and multiple logistic regression were conducted for the estimation and statistical interference.

Results

DHRs were suspected in 393 patients with 678 culprit drugs. In 183 cases, drug hypersensitivities were confirmed, mostly against nonopioid analgesic drugs and antibiotics. Multiple logistic regression analysis identified a positive association of antibiotic hypersensitivity with obesity [odds ratio (OR) 5.75, average marginal effect (AME) +24.4%] and age and a negative association with arterial hypertension, female sex, elevated immunoglobulin E (IgE), and allergic rhinitis. Hypersensitivity to nonopioid analgesics was associated with atopic dermatitis (OR 10.28, AME +28.5%), elevated IgE, and arterial hypertension.

Conclusions

Drug-specific cofactors of DHR include obesity for antibiotics and atopic dermatitis for nonopioid analgesics, the knowledge of which may improve the risk calculation for drug provocation tests.

COVID-19 vaccine provocation test outcome in high-risk allergic patients: A retrospective study from a tertiary hospital in Indonesia

Background

High COVID-19 vaccine coverage is essential. Patients who are considered high risk for hypersensitivity reactions and have had an allergic reaction to the COVID-19 vaccine are usually referred to an allergist for assessment of vaccination. Administration of a vaccine graded challenge (also known as a provocation test) is an option that can be considered in this population. This primary objective of this study is to describe the outcome of the COVID-19 vaccine provocation test and to understand the predicting factors associated with hypersensitivity reaction after the provocation test as the secondary objective.

Methods

Adult patients with a history of hypersensitivity reaction to the first COVID-19 vaccine and high-allergic patients who underwent COVID-19 vaccine provocation test up until May 2022 were included. A protocol using skin prick test (SPT), intradermal test (IDT), followed by graded challenge was developed for the determined vaccine used.

Results

A total of 232 patients were included in the analysis. Twenty-eight had hypersensitivity to their first COVID-19 vaccine dose and 204 were high risk for allergic reaction. Hypersensitivity reactions occurred in 20 patients (8.6%, 95% CI: 5-12.2%), consisting of 4 reactions after SPT, 9 after IDT, 7 during or after titrated challenge. Half of the reactions were mild; however, 3 patients developed severe reactions. Patients with history of anaphylaxis were more likely to experience hypersensitivity reaction after provocation test (aRR = 2.79, 95% CI: 1.05-7.42).

Conclusion

Provocation test in COVID-19 vaccination has a high success rate in patients with a history of hypersensitivity to the first COVID-19 vaccine and in high allergic patients. History of anaphylaxis is associated with hypersensitivity reaction after a COVID-19 vaccine provocation test.

Inherent clinical properties of non-immediate hypersensitivity to iodinated contrast media

BACKGROUND

Iodinated contrast media (ICM) is a frequently used compound in radiology. Non-immediate hypersensitivity reactions (HSR) appear when a patient leaves the department and usually are undocumented. True hypersensitivity in this group is rarely proved.

METHODS

Single-centre 2014-2018 data were retrospectively analysed. HSR to ICM were classified and investigated according to the time of occurrence (immediate <1 hour, non-immediate >1 hour). ENDA questionnaire and skin tests (prick or intradermal test) were performed according to ENDA/EAACI recommendations.

RESULTS

69 patients with a clinical history of HSR to ICM were identified, 72.46% were females (n = 50). The average age was 56 (SD ± 13.16) years. Non-immediate HSR occurred in 28.99% (n = 20) patients. The suspected culprit drugs were: iodixanol 20% (n = 4), iopromide 5% (n = 1), diatrizoate 10% (n = 2) and iohexol 10% (n = 2). Among non-immediate HSR 96.00% (n = 19) of patients had skin rashes. A statistically significant correlation was found between the clinical symptoms and the type of reaction (p-value <0.05): isolated skin manifestations mostly occurred in non-immediate HSR 75.00% (n = 15). Only 13.04% (n = 9) of all the patients were proved to be allergic to a certain ICM after the proposed diagnostic workup.

CONCLUSIONS

One-third of the hypersensitivity reactions investigated were classified as non-immediate type. Most of them manifested with isolated skin symptoms. The most frequent culprit drug encountered was iodixanol. The overall non-immediate hypersensitivity confirmation rate after diagnostic evaluation was only 15%.

New perspectives on propofol allergy

PURPOSE

Propofol is an intravenous sedative used in many patient populations and care settings. Although generally considered safe and effective, the drug has historically been avoided in patients with reported allergies to egg, soy, and/or peanut on the basis of the manufacturer's prescribing information. Concerns exist for potential adverse events, increased medication costs, reduced efficacy, and risk of medication errors when using alternative agents. Here we present a critical examination of the literature concerning cross-reactivity of food allergies with propofol to provide evidence-based recommendations for the evaluation and management of potential allergic reactions.

SUMMARY

Literature regarding the history of propofol allergy warnings and clinical trial data were assessed to provide an alternative perspective on avoidance of propofol in patients with food allergies. Suspected trigger molecules are discussed with evaluation of the antigenic potential of excipient ingredients used in the manufacture of multiple propofol formulations. Evidence-based recommendations are provided for pharmacist-led screening of adult patients with reported food allergies to support selection of propofol or alternative therapy.

CONCLUSION

There is a lack of definitive evidence that propofol must be routinely avoided in patients with reported allergies to egg, soy, and/or peanut products. Data from clinical trials suggest that propofol is safe for patients with nonanaphylactic food allergies. Patients who do experience allergic reactions following administration of propofol should undergo further testing to definitively identify the specific trigger and prevent future unnecessary avoidance of preferred medication regimens. Pharmacists can play an important role in interviewing patients with reported food allergies to better determine the risk vs benefit of propofol avoidance.

Development of early diagnosis of Parkinson's disease: Illusion or reality?

The fight against neurodegenerative diseases, Alzheimer disease and Parkinson's disease (PD), is a challenge of the 21st century. The low efficacy of treating patients is due to the late diagnosis and start of therapy, after the degeneration of most specific neurons and depletion of neuroplasticity. It is believed that the development of early diagnosis (ED) and preventive treatment will delay the onset of specific symptoms. This review evaluates methodologies for developing ED of PD. Since PD is a systemic disease, and the degeneration of certain neurons precedes that of nigrostriatal dopaminergic neurons that control motor function, the current methodology is based on searching biomarkers, such as premotor symptoms and changes in body fluids (BF) in patients. However, all attempts to develop ED were unsuccessful. Therefore, it is proposed to enhance the current methodology by (i) selecting among biomarkers found in BF in patients at the clinical stage those that are characteristics of animal models of the preclinical stage, (ii) searching biomarkers in BF in subjects at the prodromal stage, selected by detecting premotor symptoms and failure of the nigrostriatal dopaminergic system. Moreover, a new methodology was proposed for the development of ED of PD using a provocative test, which is successfully used in internal medicine.

The measurement of drug-induced interferon γ-releasing cells and lymphocyte proliferation in severe cutaneous adverse reactions

BACKGROUND

The lymphocyte transformation test (LTT) is a standard laboratory method to identify culprit drugs in patients with a history of drug-induced non-immediate hypersensitivity and is mainly performed during the recovery phase. The measurement of drug-specific interferon γ (IFN-γ)-releasing cells has been introduced to confirm culprit drugs, even during the acute phase of drug allergy.

OBJECTIVES

This study aimed to evaluate the capability of the enzyme-linked immunospot assay (ELISpot) to detect drug-specific IFN-γ-releasing cells during the acute phase and the capability of LTT to identify culprit drugs during the recovery phase in patients presenting with severe cutaneous adverse reactions (SCARs).

METHODS

Peripheral blood mononuclear cells (PBMCs) from 23 SCAR patients were collected during the acute and recovery phases and assayed for drug-specific IFN-γ-releasing cells and lymphocyte proliferation, respectively.

RESULTS

Drug-specific IFN-γ-releasing cells were detectable in 73.9% of SCAR subjects (55.6% and 85.7% in patients who were and were not taking systemic steroids, respectively), whereas LTT results were positive in 52.2% of SCAR subjects. The frequencies of drug-specific IFN-γ-releasing cells were significantly higher in patients with positive LTT than in those with negative LTT (260.1 ± 110.0 and 46.6 ± 20.7 cells/10⁶ PBMCs, P = 0.01). A significant correlation between the results of the IFN-γ ELISpot assay and LTT was demonstrated (r = 0.65, P value <0.01).

CONCLUSION

The IFN-γ ELISpot assay could be a useful tool to identify culprit drugs in SCAR patients when culprit drug identification is urgently needed during the acute phase of drug allergy.

Stamping a Case of Cutaneous Adverse Drug Reaction: Proving Beyond Causality Assessment

Different types of skin testing with a suspected drug have been reported to be helpful in determining the cause of cutaneous adverse drug reactions (CADRs). It is of utmost importance for practicing dermatologists to have a first hand knowledge of different types of skin tests available in a case of CADR. In each suspected case, a detailed investigation with the suspected agent and correlation of the positive skin reaction with clinical variant of CADR is advocated. Drug skin tests are performed 6 weeks to 6 months after complete healing of the CADR. Drug patch tests are performed similar to the methods used in patch testing in studying contact dermatitis. The commercialized form of the drug used by the patient is tested at 30% dilution. The pure drug is tested at 10% dilution. In severe CADR, drug patch tests should be performed at lower concentrations. It is also of value to test on the most affected site of the initial CADR.