Drug reaction with eosinophilia and systemic symptoms (DRESS): a multiorgan antiviral T cell response

Pathophysiology of drug hypersensitivity

Drug hypersensitivity reactions (DHRs) are type B adverse drug reactions (ADRs) traditionally defined as unpredictable, dose independent and not related to the drug pharmacology. DHRs, also called drug allergy if the immune system involvement is confirmed, represent around one-sixth of all ADRs and can cause major clinical problems due to their vague clinical presentation and irregular time course. Understanding the underlying pathophysiology of DHRs is very important for their diagnosis and management. Multiple layers of evidence exist pointing to the involvement of the immune system in DHRs. Recent data have led to a paradigm shift in our understanding of the exact pathophysiology of these reactions. Numerous hypotheses proposing explanation on how a low molecular weight drug molecule can elicit an immune reaction have been proposed. In addition to the classical "hapten" hypothesis, the reactive metabolite hypothesis, the pharmacological interaction with the immune system (p-i) concept, the danger/injury hypothesis and the altered peptide repertoire hypothesis have been proposed. We here introduce the inflammasome activation hypothesis and the cross-reactivity hypothesis as additional models explaining the pathophysiology of DHRs. Available data supporting these hypotheses are briefly summarized and discussed. We also introduced the cross-reactivity model, which may provide a platform to appreciate the potential role played by other factors leading to the activation of the immune system. We believe that although the drug in question could be the trigger of the reaction, the components of the immune system mediating the reaction do not act in isolation but rather are affected by the proinflammatory milieu occurring at the time of the reaction. This review attempts to summarize the available evidence to further illustrate the pathophysiology of DHRs.

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 Allergy Mimics

When approaching a case of apparent drug allergy, the consulting clinician should consider a broad differential diagnosis. This article presents a series of cases that could be commonly referred to an allergist for assessment as "drug allergy," however, a real diagnosis exists that mandates a different diagnostic and treatment strategy, including a case of inducible laryngeal obstruction, multiple drug intolerance syndrome, viral rash, seizure due to metastatic malignancy, and hemophagocytic lymphohistiocytosis initially diagnosed as drug reaction and eosinophilia with systemic symptoms. The initial misdiagnoses of these patients delayed or interfered with their medical care, emphasizing the importance of accurate diagnoses for the benefit of our patients.

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms. Part I. Epidemiology, pathogenesis, clinicopathological features, and prognosis

Drug-induced hypersensitivity syndrome (DiHS), also known as drug reaction with eosinophilia and systemic symptoms (DRESS), is a severe cutaneous adverse reaction (SCAR) characterized by an exanthem, fever, and hematologic and visceral organ involvement. Anticonvulsants, antibiotics, and allopurinol are the most common triggers. The pathogenesis involves a complex interplay between drugs, viruses, and the immune system primarily mediated by T-cells. DiHS/DRESS typically presents with a morbilliform eruption 2-6 weeks after drug exposure, and is associated with significant morbidity, mortality, and risk of relapse. Long-term sequelae primarily relate to organ dysfunction and autoimmune diseases. Part I of this continuing medical education activity on DiHS/DRESS provides an update on epidemiology, novel insights into pathogenesis, and a description of clinicopathological features and prognosis.

Severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs), which include Stevens-Johnson syndrome and toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (also known as drug-induced hypersensitivity syndrome), acute generalized exanthematous pustulosis, and generalized bullous fixed drug eruption, are life-threatening conditions. The pathogenesis of SCARs involves T cell receptors recognizing drug antigens presented by human leukocyte antigens, triggering the activation of distinct T cell subsets. These cells interact with keratinocytes and various immune cells, orchestrating cutaneous lesions and systemic manifestations. Genetic predisposition, impaired drug metabolism, viral reactivation or infections, and heterologous immunity influence SCAR development and clinical presentation. Specific genetic associations with distinct SCAR phenotypes have been identified, leading to the implementation of genetic screening before prescription in various countries to prevent SCARs. Whilst systemic corticosteroids and conventional immunomodulators have been the primary therapeutic agents, evolving strategies, including biologics and small molecules targeting tumour necrosis factor, different cytokines, or Janus kinase signalling pathways, signify a shift towards a precision management paradigm that considers individual clinical presentations.

Cutaneous adverse drug reactions

Cutaneous adverse drug reactions (ADRs) represent a heterogeneous field including various clinical patterns without specific features suggesting drug causality. Maculopapular exanthema and urticaria are the most common types of cutaneous ADR. Serious cutaneous ADRs, which may cause permanent sequelae or have fatal outcome, may represent 2% of all cutaneous ADR and must be quickly identified to guide their management. These serious reactions include bullous manifestations (epidermal necrolysis i.e. Stevens-Johnson syndrome and toxic epidermal necrolysis), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). Some risk factors for developing cutaneous ADRs have been identified, including immunosuppression, autoimmunity or genetic variants. All drugs can cause cutaneous ADRs, the most commonly implicated being antibiotics (especially aminopenicillins and sulfonamides), anticonvulsants, allopurinol, antineoplastic drugs, non-steroidal anti-inflammatory drugs and iodinated contrast media. Pathophysiology is related to immediate or delayed "idiosyncratic" immunologic mechanisms, i.e., usually not related to dose, and pharmacologic/toxic mechanisms, commonly dose-dependent and/or time-dependent. If an immuno-allergic mechanism is suspected, allergological explorations (including epicutaneous patch testing and/or intradermal test) are often possible to clarify drug causality, however these have a variable sensitivity according to the drug and to the ADR type. No in vivo or in vitro test can consistently confirm the drug causality. To determine the origin of a rash, a logical approach based on clinical characteristics, chronologic factors and elimination of differential diagnosis (especially infectious etiologies) is required, completed with a literature search. Reporting to pharmacovigilance system is therefore essential both to analyze drug causality at individual level, and to contribute to knowledge of the drug at population level, especially for serious cutaneous ADRs or in cases involving newly marketed drugs.

Retrospective study on the association of human herpesvirus reactivation with severe DRESS: A description of blood and skin reactivations

BACKGROUND

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) is a severe adverse event (mortality of 10%). Its pathophysiology involves herpesviruses, particularly HHV-6, but the exact mechanisms are still poorly understood.

OBJECTIVE

To describe severe cases of DRESS and especially their association with herpesvirus reactivation.

METHODS

This study was a multicentre case series conducted between 2007 and 2021 at five University Hospital Centres in France. The study included patients who had severe DRESS, which was defined as death, transfer to the intensive care unit (ICU), or severe damage to internal organs. We excluded patients without blood PCR sample, without a drug formally attributed or with RegiSCAR score < 6. We collected data on severity, causative drug, associated visceral damage and results of viral blood PCRs. HHV-6 reactivation was studied in skin biopsies by detection of small non-coding transcripts (HHV-6 miR-aU14) and a late viral protein (GP82/105).

RESULTS

Fifty-two patients were included (29 female, median age 62, interquartile range (IQR) [37;72]). Eight patients (15%) died, 13 (27%) were admitted to ICU. Most patients (n = 34; 65%) had multisystem involvement: most frequent was liver (n = 46; 88%), then renal failure (n = 24; 46%). Forty patients (77%) had at least one blood viral reactivation among HHV-6, EBV or CMV, of which 21 (53%) had at least two. Median time of blood HHV-6 reactivation was 24 days (IQR [20;35]). HHV-6 reactivation was demonstrated in 15 out of 20 skin biopsies, with a median time of 11 days [9;17].

CONCLUSIONS

We confirmed the high rate of HHV-6 reactivation in severe DRESS and demonstrated cutaneous HHV-6 reactivation using small non-coding transcripts (HHV-6 miR-aU14), which preceded viral PCR positivity in blood. These results suggest that HHV-6 reactivation during DRESS may start in skin. Furthermore, search for miR-aU14 in skin biopsy could become a useful diagnostic tool for early detection of HHV-6 reactivation.

Why drug exposure is frequently associated with T-cell mediated cutaneous hypersensitivity reactions

Cutaneous hypersensitivity reactions represent the most common manifestation of drug allergy seen in the clinic, with 25% of all adverse drug reactions appearing in the skin. The severity of cutaneous eruptions can vastly differ depending on the cellular mechanisms involved from a minor, self-resolving maculopapular rash to major, life-threatening pathologies such as the T-cell mediated bullous eruptions, i.e., Stevens Johnson syndrome/toxic epidermal necrolysis. It remains a significant question as to why these reactions are so frequently associated with the skin and what factors polarise these reactions towards more serious disease states. The barrier function which the skin performs means it is constantly subject to a barrage of danger signals, creating an environment that favors elicitation. Therefore, a critical question is what drives the expansion of cutaneous lymphocyte antigen positive, skin homing, T-cell sub-populations in draining lymph nodes. One answer could be the heterologous immunity hypothesis whereby tissue resident memory T-cells that express T-cell receptors (TCRs) for pathogen derived antigens cross-react with drug antigen. A significant amount of research has been conducted on skin immunity in the context of contact allergy and the role of tissue specific antigen presenting cells in presenting drug antigen to T-cells, but it is unclear how this relates to epitopes derived from circulation. Studies have shown that the skin is a metabolically active organ, capable of generating reactive drug metabolites. However, we know that drug antigens are displayed systemically so what factors permit tolerance in one part of the body, but reactivity in the skin. Most adverse drug reactions are mild, and skin eruptions tend to be visible to the patient, whereas minor organ injury such as transient transaminase elevation is often not apparent. Systemic hypersensitivity reactions tend to have early cutaneous manifestations, the progression of which is halted by early diagnosis and treatment. It is apparent that the preference for cutaneous involvement of drug hypersensitivity reactions is multi-faceted, therefore this review aims to abridge the findings from literature on the current state of the field and provide insight into the cellular and metabolic mechanisms which may contribute to severe cutaneous adverse reactions.

Novel insights into molecular and cellular aspects of delayed drug hypersensitivity reactions

INTRODUCTION

Delayed drug hypersensitivity reactions (DDHRs) represent a major health problem. They are unpredictable and can cause life-long disability or even death. The pathophysiology of DDHRs is complicated, multifactorial, and not well understood mainly due to the lack of validated animal models or in vitro systems. The role of the immune system is well demonstrated but its exact pathophysiology still a matter of debate.

AREA COVERED

This review summarizes the current understanding of DDHRs pathophysiology and abridges the available new evidence supporting each hypothesis. A comprehensive literature search for relevant publications was performed using PubMed, Google Scholar, and Medline databases with no date restrictions and focusing on the most recent 10 years.

EXPERT OPINION

Although multiple milestones have been achieved in our understanding of DDHRs pathophysiology as a result of the development of useful experimental models, many questions are yet to be fully answered. A deeper understanding of the mechanistic basis of DDHRs would not only facilitate the development of robust and reliable diagnostic assays for diagnosis, but would also inform therapy by providing specific target(s) for immunomodulation and potentially permit pre-therapeutic risk assessment to pursue the common goal of safe and effective drug therapy.

Immunopathogenic Insights on Preferential Human Herpesvirus-6 Reactivation in Drug Rash With Eosinophilia and Systemic Symptoms: A Scoping Review

INTRODUCTION

Human herpesvirus-6 (HHV-6) is a ubiquitous lymphotropic betaherpesvirus that can reactivate in drug rash with eosinophilia and systemic symptoms (DRESS). Despite recent publications advancing our understanding of HHV-6 in DRESS, the exact role of HHV-6 in disease pathogenesis remains unclear.

METHODS

A scoping review with the PubMed query "(HHV 6 AND (drug OR DRESS OR DIHS)) OR (HHV6 AND (drug OR DRESS OR DIHS))" was conducted in accordance with PRISMA guidelines. Articles containing original data on at least one DRESS patient with HHV-6 testing were included.

RESULTS

Our search returned a total of 373 publications, of which 89 met eligibility criteria. HHV-6 reactivation occurred in 63% of DRESS patients (n = 748), which was significantly more often than other herpesviruses. HHV-6 reactivation was associated with worse outcomes and greater severity in controlled studies. Case reports have demonstrated sometimes fatal HHV-6-related multi-organ involvement. Temporally, HHV-6 reactivation typically occurs 2 to 4 weeks after DRESS onset and has been linked to markers of immunologic signaling, such as OX40 (CD134), an HHV-6 entry receptor. Efficacy of antiviral or immunoglobulin treatment has only been demonstrated anecdotally, and steroid use may affect HHV-6 reactivation.

CONCLUSION

HHV-6 is implicated in DRESS more than in any other dermatologic condition. It is still unclear whether HHV-6 reactivation is cause or consequence of DRESS dysregulation. Similar pathogenic mechanisms precipitated by HHV-6 in other contexts may be relevant in DRESS. Future randomized controlled studies to assess effects of viral suppression on clinical outcomes is needed.

Advances in understanding of the pathogenesis and therapeutic implications of drug reaction with eosinophilia and systemic symptoms: an updated review

Drug reaction with eosinophilia and systemic symptoms or drug-induced hypersensitivity syndrome (DRESS/DIHS) is one type of severe cutaneous adverse reaction (SCAR). It is featured by fever, widespread skin lesions, protracted clinical course, internal organ involvement, and possibly long-term autoimmune sequelae. The presence of high-risk human leukocyte antigen (HLA) alleles, hypersensitivity reaction after culprit drug ingestion, and human herpesvirus reactivation may all contribute to its complex clinical manifestations. Some recent studies focusing on the roles of involved cytokines/chemokines and T cells co-signaling pathways in DRESS/DIHS were conducted. In addition, some predictors of disease severity and prognosis were also reported. In this review, we provided an update on the current understanding of the pathogenesis, potential biomarkers, and the relevant therapeutic rationales of DRESS/DIHS.

Drug Reaction With Eosinophilia and Systemic Symptoms: A Systematic Review

BACKGROUND

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a potentially life-threatening drug reaction; recognizing the diversity of its clinical presentations, implicated drugs, and management modalities can aid in diagnosis and reduce morbidity and mortality.

OBJECTIVE

To review the clinical features, drug causes, and treatments deployed in DRESS.

METHODS

This review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to review publications relating to DRESS published between 1979 and 2021. Only publications with a RegiSCAR score of 4 or greater were included (indicating "probable" or "definite" DRESS). The PRISMA guidelines were used for data extraction and the Newcastle-Ottawa scale for quality assessment (Pierson DJ. Respir Care 2009;54:1372-8). The main outcomes included implicated drugs, patient demographics, clinical manifestations, treatment, and sequelae for each included publication.

RESULTS

A total of 1124 publications were reviewed, and 131 met the inclusion criteria, amounting to 151 cases of DRESS. The most implicated drug classes were antibiotics, anticonvulsants, and anti-inflammatories, although up to 55 drugs were implicated. Cutaneous manifestations were present in 99% of cases, with a median onset of 24 days and maculopapular rash the most common morphology. Common systemic features were fever, eosinophilia, lymphadenopathy, and liver involvement. Facial edema was present in 67 cases (44%). Systemic corticosteroids were the mainstay of DRESS-specific treatment. A total of 13 cases (9%) resulted in mortality.

CONCLUSION

DRESS diagnosis should be considered in the presence of a cutaneous eruption, fever, eosinophilia, liver involvement, and lymphadenopathy. The class of implicated drug may influence outcome, as allopurinol was associated with 23% of cases that resulted in death (3 cases). Given potential DRESS complications and mortality, it is important that DRESS is recognized early so that any suspect drugs are ceased promptly.

Case report: Progressive skin rash and lymphadenopathy associated with lamotrigine−valproic acid combination in a bipolar adolescent

Background: Lamotrigine may cause severe skin reactions. There is a known interaction between lamotrigine and valproic acid with an increase in lamotrigine levels and lamotrigine toxicity risk. Few cases of severe rash and systemic reactions in bipolar patients using lamotrigine and valproate have been reported. Here, we report a rare case of severe skin rash and lymphadenopathy associated with lamotrigine−valproic acid combination.

Case presentation: An 18-year-old female adolescent with bipolar disorder type I was treated with lamotrigine, magnesium valproate, and perospirone for 12 days. After the last dose of lamotrigine, she abruptly developed generalized rash and swollen lymph nodes, which continued to progress over the next 3 days. This finally subsided after stopping valproate and with glucocorticoid treatment.

Conclusion: This case suggests that lamotrigine−valproic acid combination may cause not only rash but also lymphadenopathy. Even though the aforementioned reactions appear after the last dose of lamotrigine, it cannot be ruled out as suspicious. We recommend caution during titration of lamotrigine and valproate and early withdrawal of both when signs of hypersensitivity appear.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Focus on the Pathophysiological and Diagnostic Role of Viruses

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a heterogeneous, multiorgan and potentially life-threatening drug-hypersensitivity reaction (DHR) that occurs several days or weeks after drug initiation or discontinuation. DHRs constitute an emerging issue for public health, due to population aging, growing multi-organ morbidity, and subsequent enhanced drug prescriptions. DRESS has more consistently been associated with anticonvulsants, allopurinol and antibiotics, such as sulphonamides and vancomycin, although new drugs are increasingly reported as culprit agents. Reactivation of latent infectious agents such as viruses (especially Herpesviridae) plays a key role in prompting and sustaining aberrant T-cell and eosinophil responses to drugs and pathogens, ultimately causing organ damage. However, the boundaries of the impact of viral agents in the pathophysiology of DRESS are still ill-defined. Along with growing awareness of the multifaceted aspects of immune perturbation caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during the ongoing SARS-CoV-2-related disease (COVID-19) pandemic, novel interest has been sparked towards DRESS and the potential interactions among antiviral and anti-drug inflammatory responses. In this review, we summarised the most recent evidence on pathophysiological mechanisms, diagnostic approaches, and clinical management of DRESS with the aim of increasing awareness on this syndrome and possibly suggesting clues for future research in this field.

DRESS/DiHS syndrome induced by Propylthiouracil: a case report

BACKGROUND

Drug reaction with eosinophilia and systemic symptoms (DRESS), also known as Drug-induced hypersensitivity syndrome (DiHS), is a severe adverse drug reaction. Propylthiouracil, a member of thiouracils group, is widely used in medical treatment of hyperthyroidism. Propylthiouracil is associated with multiple adverse effects such as rash, agranulocytosis hepatitis and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, but rarely triggers DRESS/DiHS syndrome. Here, we describe a severe case of propylthiouracil-induced DRESS/DiHS syndrome.

CASE PRESENTATION

A 38-year-old female was treated with methimazole for hyperthyroidism at first. 4 weeks later, the patient developed elevated liver transaminase so methimazole was stopped. After liver function improved in 2 weeks, medication was switched to propylthiouracil therapy. The patient subsequently developed nausea and rash followed by a high fever, acute toxic hepatitis and multiple organ dysfunction (liver, lung and heart), which lasted for 1 month after propylthiouracil was started. According to the diagnostic criteria, the patient was diagnosed of DRESS/DiHS syndrome which was induced by propylthiouracil. As a result, propylthiouracil was immediately withdrawn. And patient was then treated with adalimumab, systematic corticosteroids and plasmapheresis in sequence. Symptoms were finally resolved 4 weeks later.

CONCLUSIONS

Propylthiouracil is a rare cause of the DRESS/DiHS syndrome, which typically consists of severe dermatitis and various degrees of internal organ involvement. We want to emphasize through this severe case that DRESS/DiHS syndrome should be promptly recognized to hasten recovery.

The immediate adverse drug reactions induced by ShenMai Injection are mediated by thymus-derived T cells and associated with RhoA/ROCK signaling pathway

Introduction

The mechanism of the immediate adverse drug reactions (ADRs) induced by ShenMai injection (SMI) has not been completely elucidated. Within 30 minutes, the ears and lungs of mice injected with SMI for the first time showed edema and exudation reactions. These reactions were different from the IV hypersensitivity. The theory of pharmacological interaction with immune receptor (p-i) offered a new insight into the mechanisms of immediate ADRs induced by SMI.

Methods

In this study, we determined that the ADRs were mediated by thymus-derived T cells through the different reactions of BALB/c mice (thymus-derived T cell normal) and BALB/c nude mice (thymus-derived T cell deficient) after injecting SMI. The flow cytometric analysis, cytokine bead array (CBA) assay and untargeted metabolomics were used to explain the mechanisms of the immediate ADRs. Moreover, the activation of the RhoA/ROCK signaling pathway was detected by western blot analysis.

Results

In BALB/c mice, the vascular leakage and histopathology results showed the occurrence of the immediate ADRs induced by SMI. The flow cytometric analysis revealed that CD4⁺ T cell subsets (Th1/Th2, Th17/Treg) were imbalanced. And the levels of cytokines such as IL-2, IL-4, IL12P70 and INF-γ increased significantly. However, in BALB/c nude mice, all the indicators mentioned above have not changed significantly. The metabolic profile of both BALB/c mice and BALB/c nude mice was significantly changed after injecting SMI, and the notable increase in lysolecithin level might have a greater association with the immediate ADRs induced by SMI. The Spearman correlation analysis revealed that LysoPC (18:3(6Z,9Z,12Z)/0:0) showed a significant positive correlation with cytokines. After injecting SMI, the levels of RhoA/ROCK signaling pathway-related protein increased significantly in BALB/c mice. Protein-protein interaction (PPI) showed that the increased lysolecithin levels might be related to the activation of the RhoA/ROCK signaling pathway.

Discussion

Together, the results of our study revealed that the immediate ADRs induced by SMI were mediated by thymus-derived T cells, and elucidated the mechanisms of such ADRs. This study provided new insights into the underlying mechanism of immediate ADRs induced by SMI.

Acute Liver Injury in the setting of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome with Cocaine as suspected culprit agent: A case report

Drug Reaction with Eosinophilia and Systemic Response (DRESS) syndrome is a rare hypersensitivity reaction characterized by rash, fever, lymphadenopathy, and visceral involvement. The liver is frequently involved in DRESS, with increased liver enzymes and hepatomegaly. Over 40 drugs have been implicated in the induction of DRESS, however other illicit substances have also been linked to this. Prompt identification of this syndrome is imperative for management. We report the case of patient presenting with acute liver injury and eosinophilia, who developed a rash meeting criterion for DRESS, with Cocaine as the suspected culprit agent, and was successfully treated with conservative measures.

Recurrent Leflunomide-Induced Drug Reaction With Eosinophilia and Systemic Symptom (DRESS) Syndrome Despite Prolonged Steroid Taper: A Case Report

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe adverse drug reaction characterized primarily by nonspecific systemic symptoms such as fever, a classical rash, and eosinophilia. While this is an adverse reaction more often related to medications such as anticonvulsants, many drugs have been reported to be implicated in this event. We report a case of a 35-year-old male who developed DRESS syndrome within one month of beginning leflunomide therapy. Despite treatment with a prolonged steroid taper, he developed a flare-up with transaminitis less than two months after his initial hospitalization. Our patient was managed with steroid pulse therapy and cyclosporine, which resulted in an improvement of symptoms and transaminitis. To our knowledge, only nine previous cases of leflunomide-induced DRESS syndrome have been previously reported.

A typical presentation of moxifloxacin-induced DRESS syndrome with pulmonary involvement: a case report and review of the literature

Background

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a kind of hypersensitivity drug reaction involving the skin and multiple internal organ systems. Moxifloxacin has rarely been reported to be a drug that is associated with DRESS syndrome. Lungs are less frequently involved in DRESS syndrome, but their involvements may herald more serious clinical processes. We present a rare typical case of moxifloxacin-induced DRESS syndrome with lungs involved. Valuable clinical data such as changes in the pulmonary imaging and pulmonary function tests was recorded. This case is important for the differential diagnosis of DRESS syndrome with lungs involved by providing clinical manifestations, CT imaging, pulmonary function tests, and biopsy pathological characteristics. The changes in pulmonary imaging and pulmonary function tests may help us understand the mechanism of DRESS syndrome further.

Case presentation

We report a case of a 47-year-old woman who was treated with oral moxifloxacin for community-acquired pneumonia. The patient subsequently developed a cough, fever, liver injury, skin rash, hematologic abnormalities, and shortness of breath (SOB) followed by pharyngeal herpes and peripheral neuritis. These symptoms, clinical lab index, and CT scan of the lungs improved after the withdrawal of moxifloxacin. The probability of moxifloxacin-induced DRESS syndrome was rated as “Definite”, with 7 scores graded by RegiSCAR. A literature search was also performed with “fluoroquinolones,” “moxifloxacin,” “ciprofloxacin,” “levofloxacin,” “delafloxacin,” and “DRESS” or “drug-induced hypersensitivity syndrome (DIHS)” as the keywords that were put into PubMed. The overall pulmonary involvement was approximately 9.1% (1/11). It is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. We summarized detailed clinical data, including pulmonary imaging and pulmonary function changes.

Conclusion

This is a rare reported case of DRESS syndrome with pulmonary involvement induced by moxifloxacin. Prompt recognition and correct diagnosis can promote appropriate treatment and accelerate recovery. This case is important for us as a reference in the differential diagnosis of DRESS syndrome and helps us further understand the mechanism of DRESS syndrome.

Advances in Our Understanding of the Interaction of Drugs with T-cells: Implications for the Discovery of Biomarkers in Severe Cutaneous Drug Reactions

Drugs can activate different cells of the immune system and initiate an immune response that can lead to life-threatening diseases collectively known as severe cutaneous adverse reactions (SCARs). Antibiotics, anticonvulsants, and antiretrovirals are involved in the development of SCARs by the activation of αβ naïve T-cells. However, other subsets of lymphocytes known as nonconventional T-cells with a limited T-cell receptor repertoire and innate and adaptative functions also recognize drugs and drug-like molecules, but their role in the pathogenesis of SCARs has only just begun to be explored. Despite 30 years of advances in our understanding of the mechanisms in which drugs interact with T-cells and the pathways for tissue injury seen during T-cell activation, at present, the development of useful clinical biomarkers for SCARs or predictive preclinical in vitro assays that could identify immunogenic moieties during drug discovery is an unmet goal. Therefore, the present review focuses on (i) advances in the understanding of the pathogenesis of SCARs reactions, (ii) a description of the interaction of drugs with conventional and nonconventional T-cells, and (iii) the current state of soluble blood circulating biomarker candidates for SCARs.

Potential Biomarker Identification by RNA-seq analysis in Antibiotic-related Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): a Pilot Study

One of the most severe forms of cutaneous adverse drug reactions is 'drug reaction with eosinophilia and systemic symptoms' (DRESS), hence subsequent avoidance of the causal drug is imperative. However, attribution of drug culpability in DRESS is challenging and standard skin allergy tests are not recommended due to patient safety reasons. Whilst incidence of DRESS is relatively low, between 1:1000 to 1:10,000 drug exposures, antibiotics are a commoner cause of DRESS and absence of confirmatory diagnostic test can result in unnecessary avoidance of efficacious treatment. We therefore sought to identify potential biomarkers for development of a diagnostic test in antibiotic-associated DRESS. Peripheral blood mononuclear cells (PBMCs) from a 'discovery' cohort (n = 5) challenged to causative antibiotic or control were analysed for transcriptomic profile. A panel of genes was then tested in a validation cohort (n = 6) and compared to tolerant controls and other inflammatory conditions which can clinically mimic DRESS. A scoring system to identify presence of drug hypersensitivity was developed based on gene expression alterations of this panel. The DRESS transcriptomic panel identified antibiotic-DRESS cases in a validation cohort but was not altered in other inflammatory conditions. Machine learning or differential expression selection of a biomarker panel consisting of six genes (STAC, GPR183, CD40, CISH, CD4, and CCL8) showed high sensitivity and specificity (100% and 85.7-100% respectively) for identification of the culprit drug in these cohorts of antibiotic-associated DRESS. Further work is required to determine whether the same panel can be repeated for larger cohorts, different medications, and other T cell mediated drug hypersensitivity reactions.

Idiosyncratic Drug Reactions: A 35-Year Chemical Research in Toxicology Perspective

When Larry Marnett founded Chemical Research in Toxicology, the study of idiosyncratic drug reactions (IDRs) was in its infancy. There was evidence that IDRs involve chemically reactive metabolites, and many of the papers in Chemical Research in Toxicology investigated the bioactivation of drugs. However, it became clear that not all drugs that form reactive metabolites are associated with a high risk of IDRs, and some drugs that do not appear to form reactive metabolites do cause IDRs. Some of the early Chemical Research in Toxicology papers investigated involvement of the adaptive immune system in the mechanism of IDRs, and HLA associations provided strong evidence for an immune mechanism of IDRs. This led to the question of how reactive metabolites might induce an immune response. The classic hapten hypothesis provided an obvious explanation, but a new hypothesis the danger hypothesis, added another dimension. Although there are common features to IDRs, it is becoming increasingly clear that there are also many differences in the mechanisms caused by different drugs. Other pharmacological effects of drugs may also play a role in the mechanism, and that is obviously true of IDRs caused by biological agents. The requirement for specific HLA and T-cell receptors is presumably the major factor that makes IDRs idiosyncratic. However, an innate immune response is required to prime the adaptive immune response. In contrast to the adaptive immune response, the innate immune response is unlikely to be idiosyncratic, and studies of the innate immune response to drugs may provide a much more accurate way to screen drugs for their potential to cause IDRs. For essential drugs that are known to cause IDRs, it may be possible to markedly decrease risk by a slow dose titration to induce immune tolerance. Significant progress has been made in the study of IDRs, but there is still a long way to go.

Late sequelae of drug reaction with eosinophilia and systemic symptoms (DRESS) cause thyroid dysfunction and thyroiditis: review of literature

Drug reaction with eosinophilia and systemic symptoms (DRESS) is one of the severe cutaneous adverse drug reactions (SCARs) with high mortality rate and variable long term sequelae, especially in thyroid dysfunction and thyroiditis. In this article, we review clinical course, culprit drugs, onset of diagnosis, and type of thyroid dysfunction in DRESS patients. There were a total of 51 cases including 12 children (aged less than 18 years old) and 39 adults from our review. The most common thyroid dysfunction was Hashimoto's thyroiditis (41/51=80.4%) including anti-thyroid antibody positive (29/51=56.9%), possible/compatible with Hashimoto's thyroiditis (12/51=23.5%) both in the children (n=12) and adult (n=39), Graves' disease/hyperthyroidism (7/51=13.7%) and non-specific hypothyroidism (3/51=5.9%), respectively. The most common culprit drugs and onset of thyroid dysfunction after DRESS diagnosis in children aged less than 18 years include antiepileptic drugs (phenytoin, phenobarbital, carbamazepine) (range 0-8 months, median 2 months) and sulfa groups (sulfasalazine, sulfamethoxazole, sulfonamide) (range 1-4 months, median 2 months). Data of prevalence, type, and clinical course of thyroid dysfunction from DRESS is important for clinicians to recognize for monitoring its sequelae and provide plans for treatment.

Advances in the Pathomechanisms of Delayed Drug Hypersensitivity

Delayed drug hypersensitivity continues to contribute to major clinical problems worldwide. The clinical presentations of delayed drug hypersensitivity are diverse, ranging from mild skin rashes to life-threatening systemic reactions. The pathomechanism of delayed drug hypersensitivity involves human leukocyte antigens (HLA) presentation of drugs/metabolites to T cell receptors (TCR), resulting in T-cell activation. The pathogenesis of delayed drug hypersensitivity also has reactivation of the virus, and activation of many immune mediators. In this review, we discuss the immune pathogenesis, molecular interactions of HLA/drugs/TCR, and downstream signaling of cytotoxic proteins/cytokines/chemokines, as well as disease prevention and management for delayed drug hypersensitivity.

Drug Reaction with Eosinophilia and Systemic Symptoms (DReSS)/Drug-Induced Hypersensitivity Syndrome (DiHS)-Readdressing the DReSS

Drug reaction with eosinophilia and systemic symptoms (DReSS), also known as drug-induced hypersensitivity syndrome (DiHS), is a severe, systemic, T cell mediated drug reaction with combinations of cutaneous, hematologic, and internal organ involvement. Pathogenesis of DReSS is multi-factorial, involving drug-exposure, genetic predisposition through specific human leukocyte antigen (HLA) alleles and metabolism defects, viral reactivation, and immune dysregulation. Clinical features of this condition are delayed, stepwise, and heterogenous, making this syndrome challenging to recognize and diagnose. Two sets of validated diagnostic criteria exist that can be employed to diagnose DReSS/DiHS. Methods to improve early recognition of DReSS and predict disease severity has been a recent area of research focus. In vitro and in vivo tests can be employed to confirm the diagnosis and help identify culprit drugs. The mainstay treatment of DReSS is prompt withdrawal of the culprit drug, supportive treatment, and immunosuppression depending on the severity of disease. We present a comprehensive review on the most recent research and literature on DReSS, with emphasis on pathogenesis, clinical features, diagnosis, confirmatory testing modalities, and treatment. Additionally, this summary aims to highlight the differing viewpoints on this severe disease and broaden our perspective on the condition known as DReSS.

Drug reaction with eosinophilia and systemic symptoms: An emergency medicine focused review

INTRODUCTION

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe drug reaction associated with potentially severe morbidity and mortality.

OBJECTIVE

This narrative review evaluates the pathogenesis, diagnosis, and management of DRESS for emergency clinicians.

DISCUSSION

DRESS is a severe hypersensitivity reaction which can involve multiple organ systems, including the skin, lymphatic system, lungs, kidneys, and heart. Treatment is primarily supportive care combined with removal of the offending agent and initiation of corticosteroids. Additional options include cyclophosphamide, cyclosporine, intravenous immunoglobulin, and N-acetylcysteine.

CONCLUSION

It is important for the emergency clinician to be aware of the diagnosis and management of DRESS in order to best optimize care for these patients.

Drug reaction with eosinophilia and systemic symptoms (DRESS) induced by phenytoin re-exposure: case report and systematic review

Introduction: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an adverse and severe skin reaction due to patients' susceptibility to medications, including phenytoin. The objective was to explore the characteristics of patients with DRESS secondary to phenytoin through a systematic review.Methods: We describe a case of DRESS syndrome secondary to phenytoin in a patient with previous exposure to this drug. A systematic literature review of cases of phenytoin-induced DRESS syndrome was conducted in PubMed/Medline, Scopus and Web of Science until May 2019.Results: 37 articles describing 40 cases of DRESS syndrome were selected. Mean age of onset was 33 years, without gender difference. Symptoms started between two and 90 days (mean ± 23 days). Liver and respiratory tract were most frequently involved, and eosinophilia was a common feature, it was presented with an average value of 9.7%. A discussion of the case and qualitative synthesis of the evidence reported in the literature were made.Conclusion: Patients and presentation characteristics will mostly be presented according to the criteria used by RegiSCAR. It is recommended to consider adequate monitoring of adverse reactions to antiepileptic drugs such as DRESS syndrome, given its severity and high lethality.

Cutaneous and systemic hyperinflammation drives maculopapular drug exanthema in severely ill COVID-19 patients

BACKGROUND

Coronavirus disease-2019 (COVID-19) has been associated with cutaneous findings, some being the result of drug hypersensitivity reactions such as maculopapular drug rashes (MDR). The aim of this study was to investigate whether COVID-19 may impact the development of the MDR.

METHODS

Blood and skin samples from COVID-19 patients (based on a positive nasopharyngeal PCR) suffering from MDR (COVID-MDR), healthy controls, non-COVID-19-related patients with drug rash with eosinophilia and systemic symptoms (DRESS), and MDR were analyzed. We utilized imaging mass cytometry (IMC) to characterize the cellular infiltrate in skin biopsies. Furthermore, RNA sequencing transcriptome of skin biopsy samples and high-throughput multiplexed proteomic profiling of serum were performed.

RESULTS

IMC revealed by clustering analyses a more prominent, phenotypically shifted cytotoxic CD8+ T cell population and highly activated monocyte/macrophage (Mo/Mac) clusters in COVID-MDR. The RNA sequencing transcriptome demonstrated a more robust cytotoxic response in COVID-MDR skin. However, severe acute respiratory syndrome coronavirus 2 was not detected in skin biopsies at the time point of MDR diagnosis. Serum proteomic profiling of COVID-MDR patients revealed upregulation of various inflammatory mediators (IL-4, IL-5, IL-6, TNF, and IFN-γ), eosinophil and Mo/Mac -attracting chemokines (MCP-2, MCP-3, MCP-4 and CCL11). Proteomics analyses demonstrated a massive systemic cytokine storm in COVID-MDR compared with the relatively milder cytokine storm observed in DRESS, while MDR did not exhibit such features.

CONCLUSION

A systemic cytokine storm may promote activation of Mo/Mac and cytotoxic CD8+ T cells in severe COVID-19 patients, which in turn may impact the development of MDR.

The association of CD4 lymphocyte count with drug hypersensitivity reaction to highly active antiretroviral therapy, trimethoprim sulfamethoxazole, and antitubercular agents in human immunodeficiency virus patients

Background

The introduction of highly active antiretroviral therapy (HAART) and antibiotic regimens for the treatment of human immunodeficiency virus (HIV) and its concomitant opportunistic infections, respectively, significantly improve the morbidity and mortality of the infected patients. However, these drugs commonly cause drug hypersensitivity reactions (DHRs) in patients with acquired immunodeficiency syndrome. The reason proposed are multifactorial, which includes immune hyperactivation, changes in drug metabolism, patient cytokine profiles, oxidative stress, genetic predisposition, and the principal target in HIV patients, the CD4+ lymphocytes.

Objective

This study determined the association of CD4 count and DHRs to first-line HAART, trimethoprim sulfamethoxazole, and antitubercular agents among HIV patients.

Methods

This is a retrospective analytical study. Review of charts were done. The demographic and clinical profile used a descriptive statistics such as mean and standard deviation for quantitative data and frequency and percent for categorical data. Chi-square and Fisher exact tests were used to measure the degree of the relationship of CD4 count and DHRs.

Results

A total of 337 eligible patients were included. There was a 25% incidence of hypersensitivity reactions. However, the prevalence of DHRs across the different CD4 groups was not statistically significant (p = 0.167). Likewise, the study found no significant association between the CD4 count and DHRs to first-line HAART, trimethoprim sulfamethoxazole, and antitubercular agents (p = 0.311). The most common DHR was morbilliform rash, and nevirapine was the most reported antiretroviral drug causing DHR.

Conclusion

There was no association in the CD4 count and DHRs to first-line HAART, trimethoprim sulfamethoxazole, and antitubercular agents. Hence, regardless of the baseline CD4 lymphocyte count, the physician should be vigilant in monitoring hypersensitivity reactions. Patient education on common DHRs is very important upon diagnosis of HIV and/or initiation of treatment.

Drug Reaction With Eosinophilia and Systemic Symptom (DRESS) Following Rifampicin Treatment: A Case Report

Drug reaction with eosinophilia and systemic symptoms (DRESS) is an idiosyncratic severe cutaneous adverse reaction (SCAR) characterized by a skin rash with systemic involvement (e.g., hematological, solid organ abnormalities). Various medications, most commonly anticonvulsants (carbamazepine, phenytoin), antibiotics (vancomycin, amoxicillin), and sulfa drugs (dapsone, sulfasalazine), have been implicated. We report a case of a 75-year-old man with pulmonary tuberculosis under anti-tubercular treatment (ATT Category 1 as per the national guidelines of Nepal) presenting with rash, fever, liver dysfunction, and eosinophilia, a combination of features suggestive of DRESS. According to the national tuberculosis (TB) survey of 2018-2019, over 117,000 people in Nepal were living with TB, including 69,000 newly diagnosed people. In third-world countries, such as Nepal, with a high TB prevalence, and the Southeast Asian region (with a huge percentage of the global burden of ‎TB‎ incidence), the risk of life-threatening adverse drug reactions during ATT is high. However, a good response is seen if it is recognized early and on stopping ATT and receiving a course of steroids and emollients.

DiHS/DRESS syndrome induced by second-line treatment for tuberculosis and Epstein-Barr virus

Drug-induced hypersensitivity syndrome (DiHS) or drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a severe adverse drug-induced reaction characterized by various symptoms: skin rash, fever, lymph node enlargement and internal organ involvement, which starts within 2 weeks to 3 months after drug initiation. It is challenging to diagnose this syndrome due to the variety of cutaneous and visceral symptoms. Different mechanisms have been implicated in its development, including genetic susceptibility associated with human leucocyte antigen (HLA) loci, detoxification defects leading to reactive metabolite formation and subsequent immunological reactions, slow acetylation, and reactivation of human herpes, including Epstein-Barr virus and human herpes virus (HHV)-6 and HHV-7. The most frequently reported causes of DiHS/DRESS are antiepileptic agents, allopurinol and sulfonamides. We report a case of DiHS/DRESS induced by second-line treatment for tuberculosis, prothionamide and para-aminosalicylic acid, and Epstein-Barr virus re-infection. Patch testing, which was performed in this case, is not fully standardized, but it can be helpful and a safe way to evaluate and diagnose DiHS/DRESS.

Is steroid pulse therapy a suitable treatment for drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms? A systematic review of case reports in patients treated with corticosteroids in Japan

Drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms is a life-threatening severe cutaneous adverse reaction, characterized by multiple organ involvement and reactivation of herpes viruses. Although the mainstay of treatment is a high dosage of corticosteroids delivered by pulse therapy or conventional oral administration, it remains debatable which mode is better. To clarify this issue, we reviewed publications in Japan of 299 cases of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms treated with corticosteroids, to evaluate safety concerns with regards to these two modes of treatment. As a result, we found that patients treated with pulse therapy more frequently suffered cytomegalovirus reactivation, persistency, and high mortality but less frequently experienced herpesvirus 6 reactivation or type 1 diabetes compared with those undergoing conventional treatment, suggesting that the administration mode may differentially modulate inflammatory responses toward distinct consequences. This is the first statistical analysis revealing that steroid pulse therapy frequently resulted in severe sequelae with high mortality. In terms of the risk of serious consequences, we consider that steroid pulse therapy should be eschewed for the treatment of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms.

Drug-induced hypersensitivity syndrome caused by minodronic acid hydrate

BACKGROUND

Drug-induced hypersensitivity syndrome (DIHS)/drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is an important adverse reaction caused by a few drugs. Reactivation of human herpesvirus 6 (HHV-6) is known to be associated with its pathogenesis. DIHS occasionally manifests as pulmonary lesions with a variety of imaging findings.

CASE PRESENTATION

An 83-year-old woman started taking minodronic acid hydrate 5 years before admission. She noticed a generalized skin rash 44 days before admission and started oral betamethasone-d-chlorpheniramine maleate combination tablets for allergic dermatitis. She developed a fever and cough in addition to the rash, and was referred to our hospital. Laboratory data showed a high level of eosinophils and liver and biliary enzymes. Computed tomography (CT) studies revealed bilateral diffuse ground-glass opacities with ill-defined centrilobular nodules from the central to peripheral regions of the lungs. Transbronchial lung cryobiopsy specimens showed that lymphocyte infiltration was observed in the alveolar walls and fibrinous exudates and floating macrophages in the alveolar lumina. Immunohistochemistry of biopsy specimens showed more CD4⁺ lymphocytes than CD8⁺ lymphocytes, while few Foxp3⁺ lymphocytes were recognized. The serum anti-HHV-6 immunoglobulin G titer increased at 3 weeks after the first test. Based on these findings, we diagnosed her with DIHS. We continued care without using corticosteroids since there was no worsening of breathing or skin condition. Eventually, her clinical symptoms chest CT had improved. Minodronic acid hydrate was identified as the culprit drug based on the positive results of the patch test and drug-induced lymphocyte stimulation test.

CONCLUSIONS

We described the first case of DIHS caused by minodronic acid hydrate. Lung lesions in DIHS can present with bilateral diffuse ground-glass opacities and ill-defined centrilobular nodules on a CT scan during the recovery phase. Clinicians should be aware of DIHS, even if patients are not involved with typical DIHS/DRESS-causing drugs.

Inflammatory complications of CGRP monoclonal antibodies: a case series

BACKGROUND

Calcitonin gene-related peptide (CGRP) is expressed throughout the body and is a known mediator of migraine, exerting this biological effect through activation of trigeminovascular, meningeal and associated neuronal pathways located in close proximity to the central nervous system. Monoclonal antibodies (mAb) targeting the CGRP pathway are an effective new preventive treatment for migraine, with a generally favourable adverse event profile. Pre-clinical evidence supports an anti-inflammatory/immunoregulatory role for CGRP in other organ systems, and therefore inhibition of the normal action of this peptide may promote a pro-inflammatory response.

CASES

We present a case series of eight patients with new or significantly worsened inflammatory pathology in close temporal association with the commencement of CGRP mAb therapy.

CONCLUSION

This case series provides novel insights on the potential molecular mechanisms and side-effects of CGRP antagonism in migraine and supports clinical vigilance in patient care going forward.

Specific features of amoxicillin-associated Drug Reaction with Eosinophilia and Systemic Symptoms syndrome: a nationwide study

BACKGROUND

Growing evidence indicates that amoxicillin induces herpesvirus replication in vitro. As these play a central pathophysiological role in Drug Reaction with Eosinophilia and Systemic Symptoms syndrome (DRESS), amoxicillin could present with specific DRESS features.

OBJECTIVE

To characterize the onset patterns of amoxicillin-associated DRESS.

METHODS

All cases of DRESS (Kardaun score ≥4) involving amoxicillin and reported in the French Pharmacovigilance Database between January 1, 2004 and November 30, 2019 were included. Onset circumstances for these cases were categorized considering the onset delay from amoxicillin initiation, and the presence of concomitant medications with a compatible time to onset.

RESULTS

A total of 146 probable cases or definite cases of DRESS were included. Three onset circumstances were identified: (i) 'amoxicillin clear culprit' where amoxicillin was the sole suspect drug or when concomitant drugs of compatible time to onset were not reported to cause DRESS (n = 62); (ii) 'amoxicillin possible culprit' in the presence of other potentially culprit drugs in addition to amoxicillin (n = 44) and (iii) 'flare' where amoxicillin, used after DRESS onset, induced flare-up reactions (n = 40). The median time to onset was 5 days (IQR 2-11) in 'clear culprit', and 18 days (IQR 7-26) in 'possible culprit' cases. In 'flare' cases, the median latency between amoxicillin initiation and flare-up reactions was 3 days (IQR 2-5).

CONCLUSIONS

Amoxicillin can induce DRESS with a specific early onset and exacerbate DRESS from another drug.

Association of human leukocyte antigen-B*13:01 with dapsone-induced liver injury

Human leukocyte antigens (HLA) have been linked to adverse drug reactions. Generally, HLA association is phenotype specific and is related to either liver or skin injury. HLA-A*13:01 has been linked to dapsone-induced severe cutaneous drug reactions and its role in drug-induced liver injury (DILI) is unclear. In our series, all of the four patients with immunoallergic dapsone DILI were carrying HLA-B*13:01 compared to its prevalence of 1-12% among Indians. HLA-B*13:01 plays a role not only in dapsone-induced severe cutaneous adverse reaction (SCAR) but also in dapsone-induced liver injury with immunoallergic features and highlights the role of adaptive immune response in the pathogenesis of both liver and skin injury and associated other organ involvement.

Skin Resident Memory T Cells May Play Critical Role in Delayed-Type Drug Hypersensitivity Reactions

Delayed-type drug hypersensitivity reactions (dtDHR) are immune-mediated reactions with skin and visceral manifestations ranging from mild to severe. Clinical care is negatively impacted by a limited understanding of disease pathogenesis. Though T cells are believed to orchestrate disease, the type of T cell and the location and mechanism of T cell activation remain unknown. Resident memory T cells (T_RM) are a unique T cell population potentially well situated to act as key mediators in disease pathogenesis, but significant obstacles to defining, identifying, and testing T_RM in dtDHR preclude definitive conclusions at this time. Deeper mechanistic interrogation to address these unanswered questions is necessary, as involvement of T_RM in disease has significant implications for prediction, diagnosis, and treatment of disease.

Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Series of 49 French Pediatric Cases

BACKGROUND

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare and potentially fatal adverse reaction. It can be difficult to diagnose, even more so among children, because symptoms may mimic other commonly encountered pediatric conditions.

OBJECTIVE

To describe clinical and laboratory features of DRESS syndrome in the pediatric population (age ≤18 years) and establish causative agents and treatment modalities.

METHODS

This was a multicenter retrospective study of probable and definite DRESS cases (Registry of Sever Cutaneous Adverse Reaction score ≥ 4) in children hospitalized in 15 French university hospitals between 2000 and 2020.

RESULTS

We included 49 cases. All children had fever and rash, 69.4% had lymphadenopathy, and 65.3% had facial edema. The most common organ affected was the liver (83.7%). Treatment consisted of topical corticosteroid in only 30.6% and systemic corticosteroid in 55.1%; 12.2% received intravenous immunoglobulin. Among probable and likely culprit drugs, 65% were antibiotics and 27.5% were antiepileptics, median time to DRESS symptom onset after initiation of 15 days (13 days with antibiotics and 21 days with antiepileptics). Twenty-seven children had allergy assessment for causative agents, 65.4% of whom had positive tests.

CONCLUSIONS

Culprit drugs are frequently antibiotics and antiepileptic drugs, and onset is often less than 2 weeks after treatment starts, especially with antibiotics. Treatment with topical corticosteroids appears to be sufficient in the least severe cases. Treatment by systemic corticosteroid therapy remains the reference treatment in case of severe organ damage.

Successful mepolizumab treatment for DRESS-induced refractory eosinophilic myocarditis and concurrent thyroiditis

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a potentially life-threatening adverse drug reaction with a mortality rate of 10%. Interstitial nephritis, pneumonitis, myocarditis, meningitis, thyroiditis and pancreatitis are major causes of morbidity and mortality in this syndrome. Cessation of offending medication is paramount. There is paucity in high quality prospective studies guiding the treatment of DRESS, and there are no published therapeutic clinical trials in the treatment of corticosteroid refractory hypersensitivity myocarditis. The authors present a unique case of ciprofloxacin-induced DRESS with concurrent thyroiditis and refractory eosinophilic myocarditis that required mepolizumab and multiple immunosuppressants for successful treatment.

Drug and Chemical Allergy: A Role for a Specific Naive T-Cell Repertoire?

Allergic reactions to drugs and chemicals are mediated by an adaptive immune response involving specific T cells. During thymic selection, T cells that have not yet encountered their cognate antigen are considered naive T cells. Due to the artificial nature of drug/chemical-T-cell epitopes, it is not clear whether thymic selection of drug/chemical-specific T cells is a common phenomenon or remains limited to few donors or simply does not exist, suggesting T-cell receptor (TCR) cross-reactivity with other antigens. Selection of drug/chemical-specific T cells could be a relatively rare event accounting for the low occurrence of drug allergy. On the other hand, a large T-cell repertoire found in multiple donors would underline the potential of a drug/chemical to be recognized by many donors. Recent observations raise the hypothesis that not only the drug/chemical, but also parts of the haptenated protein or peptides may constitute the important structural determinants for antigen recognition by the TCR. These observations may also suggest that in the case of drug/chemical allergy, the T-cell repertoire results from particular properties of certain TCR to recognize hapten-modified peptides without need for previous thymic selection. The aim of this review is to address the existence and the role of a naive T-cell repertoire in drug and chemical allergy. Understanding this role has the potential to reveal efficient strategies not only for allergy diagnosis but also for prediction of the immunogenic potential of new chemicals.