Update on pathobiology in Stevens-Johnson syndrome and toxic epidermal necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) are rare but life-threatening severe cutaneous adverse reactions (SCARs), which are mainly induced by a variety of drugs. Once considered to be unpredictable, significant progress has been achieved in understanding the pathological mechanisms underlying such reactions. Recent studies suggested that SJS/TEN is a specific immune reaction where human leukocyte antigen (HLA) alleles specific for certain drugs in defined populations are involved in the activation of cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells. Upon the activation, various cytotoxic and immunological signals, including but not limited to Fas/Fas ligand, perforin/granzyme B, and granulysin are launched to mediate the disseminated keratinocyte death in SJS/TEN. This review provides an update on the pathobiology of SJS/TEN in both the genomic and immunologic perspectives. The knowledge gained from these cutting-edge studies will form the basis for better prevention and management of SJS/TEN.     

Pharmacogenetics of cutaneous adverse drug reactions

Drug-induced hypersensitivity reactions are of major medical concern because they are associated with high morbidity and high mortality. In addition, individual patients' reactions are impossible to predict in each patient. In the field of severe cutaneous adverse drug reactions (cutaneous ADR) such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug-induced hypersensitivity syndrome (DHIS) or drug rash with eosinophilia and systemic symptoms (DRESS), major advances have recently been gained through studies of an association between HLA alleles and drug hypersensitivity induced by specific drugs. The results of these pharmacogenomic studies allow prediction of the risk of adverse reactions in patients treated with certain drugs, including carbamazepine and other aromatic antiepileptic drugs, allopurinol and abacavir. However, different ethnic populations show variations in the genetic associations. A strong association between carbamazepine-induced SJS/TEN and HLA-B*1502 has been found in Southeast Asian patients but not in Caucasian and Japanese patients. Moderate associations between aromatic amine anticonvulsants and other HLA alleles have been proposed in Japanese patients. In contrast, HLA-B*5801 was found to be associated with allopurinol-induced cutaneous ADR, including SJS/TEN and DIHS/DRESS, in Caucasian and Asian patients, including the Japanese. These differences may, at least in part, be due to the differences in allele frequency in different ethnic populations. This article reviews the progress in pharmacogenomics, associated mainly with carbamazepine and allopurinol in different ethnic populations. Pharmacogenetic screening based on associations between adverse reactions and specific HLA alleles helps to avoid serious conditions associated with drug hypersensitivity.     

Association of HLA-B*1502 allele with carbamazepine-induced toxic epidermal necrolysis and Stevens-Johnson syndrome in the multi-ethnic Malaysian population

Background Carbamazepine (CBZ), a frequently used anticonvulsant drug, is one of the most common causes of life‐threatening cutaneous adverse drug reactions such as toxic epidermal necrolysis (TEN) and Stevens–Johnson syndrome (SJS). Recent studies have revealed a strong association between HLA‐B*1502 and CBZ‐induced TEN/SJS in the Taiwan Han Chinese population. Objectives This study is aimed to investigate the association between human leucocyte antigens (HLA) and CBZ‐induced TEN/SJS in the multi‐ethnic Malaysian population. Methods A sample of 21 unrelated patients with CBZ‐induced TEN/SJS and 300 race‐matched, healthy controls were genotyped for HLA‐A, ‐B and ‐DR using polymerase chain reaction (PCR). Allele frequencies were compared. Results HLA‐B*1502 was present in 75.0% (12/16) of Malay patients with CBZ‐induced TEN/SJS but in only 15.7% (47/300) of normal controls (odds ratio 16.15, 95% confidence interval 4.57–62.4; corrected P‐value = 7.87 × 10^?6), which suggests a strong association between HLA and CBZ‐induced TEN/SJS. Additionally, HLA‐B*1502 was found in all three Chinese and two Indian patients. Existing data show that frequencies of the HLA‐B*1502 allele are generally much higher in Asian populations than in White European populations, which explains the higher incidences of SJS and TEN in Asian countries. Conclusions HLA‐B*1502 is strongly associated with CBZ‐induced TEN/SJS in the Malay population in Malaysia, as has been seen in Han Chinese in Taiwan. This indicates that the genetic association apparent in the incidence of CBZ‐induced TEN/SJS is linked with the presence of HLA‐B*1502, irrespective of racial origin. Screening of patients for this genetic marker can help to prevent the occurrence of TEN/SJS.     

Cutaneous adverse drug reactions seen in a tertiary hospital in Johor,Malaysia

Background Adverse drug reactions are most commonly cutaneous in nature. Patterns of cutaneous adverse drug reactions (ADRs) and their causative drugs vary among the different populations previously studied. Objective Our aim is to determine the clinical pattern of drug eruptions and the common drugs implicated, particularly in severe cutaneous ADRs in our population. Materials and Methods This study was done by analyzing the database established for all adverse cutaneous drug reactions seen from January 2001 until December 2008. Results A total of 281 cutaneous ADRs were seen in 280 patients. The most common reaction pattern was maculopapular eruption (111 cases, 39.5%) followed by Stevens‐Johnson Syndrome (SJS: 79 cases, 28.1%), drug reaction with eosinophilia and systemic symptoms (DRESS: 19 cases, 6.8%), toxic epidermal necrolysis (TEN: 16 cases, 5.7 %), urticaria/angioedema (15 cases, 5.3%) and fixed drug eruptions (15 cases, 5.3%). Antibiotics (38.8%) and anticonvulsants (23.8%) accounted for 62.6% of the 281 cutaneous ADRs seen. Allopurinol was implicated in 39 (13.9%), carbamazepine in 29 (10.3%), phenytoin in 27 (9.6%) and cotrimoxazole in 26 (9.3%) cases. Carbamazepine, allopurinol and cotrimoxazole were the three main causative drugs of SJS/TEN accounting for 24.0%, 18.8% and 12.5% respectively of the 96 cases seen whereas DRESS was mainly caused by allopurinol (10 cases, 52.6%) and phenytoin (3 cases, 15.8%). Discussion The reaction patterns and drugs causing cutaneous ADRs in our population are similar to those seen in other countries although we have a much higher proportion of severe cutaneous ADRs probably due to referral bias, different prescribing habit and a higher prevalence of HLA‐B*1502 and HLA‐B*5801 which are genetic markers for carbamazepine‐induced SJS/TEN and allopurinol‐induced SJS/TEN/DRESS respectively. Conclusion The most common reaction pattern seen in our study population was maculopapular eruptions. Antibiotics, anticonvulsants and NSAIDs were the most frequently implicated drug groups. Carbamazepine and allopurinol were the two main causative drugs of severe ADRs in our population.     

HLA-A31 strongly associates with carbamazepine-induced adverse drug reactions but not with carbamazepine-induced lymphocyte proliferation in a Japanese population

Carbamazepine (CBZ) is the most frequent culprit drug for severe cutaneous adverse drug reactions (ADR), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN) and drug-induced hypersensitivity syndrome (DIHS). A strong association between human leukocyte antigen (HLA)-B*1502 and CBZ-induced SJS/TEN has been reported in Han Chinese, Thai, Malaysian and Indian populations, but not in Caucasian or Japanese populations. Recent studies showed an association between HLA-A*3101 and CBZ-induced ADR in Caucasian and Japanese populations. We conducted a case-control study to determine HLA genotyping of patients with CBZ-induced ADR in a Japanese population. Fifteen patients with CBZ-induced ADR and 33 subjects who had taken CBZ for more than 3 months without evidence of any ADR as a control were enrolled. In addition, the results of a CBZ-induced lymphocyte stimulation test were compared between the groups. A strong association was found between HLA-A31 and CBZ-induced ADR (P < 0.001), and a weak association was found between HLA-A11 and HLA-B51 with CBZ-induced ADR. No HLA-B*1502 was found in either patients or control subjects. The mean CBZ-induced lymphocyte stimulation index was significantly high in patients with CBZ-induced ADR compared with CBZ-tolerant patients (P < 0.001); however, no significant difference was seen between HLA-A31-positive subjects and HLA-A31-negative subjects in either group. These findings suggest that HLA-A31 is strongly associated with CBZ-induced ADR in the Japanese, but does not determine CBZ-induced lymphocyte proliferation.     

A patch testing and cross‐sensitivity study of carbamazepine‐induced severe cutaneous adverse drug reactions

Background The usefulness of the drug patch testing for Stevens–Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) is still controversial. Recent studies have shown that HLA‐B*1502 is strongly associated with CBZ‐SJS/TEN in Chinese and Southeast Asian populations. Objective To evaluate the usefulness of patch tests for patients with carbamazepine (CBZ)‐induced SJS, TEN and drug reaction with eosinophilia and systemic symptoms (DRESS) and the cross‐reactivity in patch tests among the aromatic antiepileptic drugs. Methods We measure the frequency of positive patch test reactions and cross‐sensitivity to structure‐related aromatic anti‐epileptic drugs (AEDs) for patients after SJS/TEN or DRESS episodes caused by CBZ. CBZ and other structure‐related AEDs used for patch testing were prepared in 10% and 30% petrolatum. Secondary measures included the association of HLA‐B*1502 genotype and frequency of possible side effects from the patch tests. Results Positive patch test reactions to 30% CBZ in the CBZ‐SJS/TEN were 62.5% (10/16), and 70% (7/10) in the CBZ‐DRESS. None of the 10 healthy controls displayed a positive reaction to tested agents. Cross‐sensitivity to other aromatic AEDs was observed in both the CBZ‐SJS/TEN and the CBZ‐DRESS. Only the HLA‐B*1502 genotype was present and strongly associated with the CBZ‐SJS/TEN, but not with the CBZ‐DRESS. Conclusion Drug patch testing is a safe and useful method for the identification of CBZ as the culprit drug of SJS/TEN as well as DRESS. Testing of chemically or pharmacologically related AEDs may provide information on cross‐reactivity for these patients.     

Severe cutaneous adverse drug reactions

The clinical manifestations of drug eruptions can range from mild maculopapular exanthema to severe cutaneous adverse drug reactions (SCAR), including drug‐induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms, Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) which are rare but occasionally fatal. Some pathogens may induce skin reactions mimicking SCAR. There are several models to explain the interaction of human leukocyte antigen (HLA), drug and T‐cell receptor (TCR): (i) the “hapten/prohapten” theory; (ii) the “p‐i concept”; (iii) the “altered peptide repertoire”; and (iv) the “altered TCR repertoire”. The checkpoints of molecular mechanisms of SCAR include specific drug antigens interacting with the specific HLA loci (e.g. HLA‐B*15:02 for carbamazepine‐induced SJS/TEN and HLA‐B*58:01 for allopurinol‐induced SCAR), involvement of specific TCR, induction of T‐cell‐mediated responses (e.g. granulysin, Fas ligand, perforin/granzyme B and T‐helper 1/2‐associated cytokines) and cell death mechanism (e.g. miR‐18a‐5p‐induced apoptosis; annexin A1 and formyl peptide receptor 1‐induced necroptosis in keratinocytes). In addition to immune mechanism, metabolism has been found to play a role in the pathogenesis of SCAR, such as recent findings of strong association of CYP2C9*3 with phenytoin‐induced SCAR and impaired renal function with allopurinol SCAR. With a better understanding of the mechanisms, effective therapeutics and prevention for SCAR can be improved.     

内蒙古汉族Stevens-Johnson综合征/中毒性表皮坏死松解症患者致敏药物及HLA基因筛查

【摘要】 目的 总结内蒙古汉族Stevens-Johnson综合征/中毒性表皮坏死松解症（SJS/TEN）患者致敏药物及筛查易感基因。方法 内蒙古医科大学附属医院皮肤科2015—2019年确诊的68例汉族SJS/TEN患者,抽取外周血提取DNA,采用PCR筛查HLA-B*5801、HLA-B*1502、HLA-A*3101等位基因。收集患者的临床资料,参照基因分型,分析致敏药物。结果 68例SJS/TEN患者,男36例,女32例,年龄46.06 ± 19.97（3 ~ 84）岁。检出HLA-B*5801阳性5例,4例为别嘌醇致敏;HLA-B*1502阳性14例,5例为卡马西平、4例为拉莫三嗪致敏,5例致敏/可疑致敏药物为抗菌药物、解热镇痛药等;HLA-A*3101阳性1例,可疑致敏药物为中药活血针剂,成分不清。结论 HLA-B*5801对别嘌醇、HLA-B*1502对卡马西平和拉莫三嗪的预测性良好,建议用药前筛查,而HLA-A*3101在本地区人群阳性率不高。     

Epidermal necrolysis: 60 years of errors and advances

Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare conditions characterized by extensive epidermal detachment and mucositis. Both are associated with a high mortality rate and significant long‐term morbidity. Since the initial report introducing the term TEN in 1956, diagnosis of the condition has been fraught with difficulties that continue to exist today. The terms ‘erythema multiforme major’ (EMM) and SJS, and their relationship to TEN have also been confusing to clinicians. It is now recognized that EMM is a different entity from SJS and TEN in terms of demographics, causality and severity. SJS and TEN represent a continuum of disease, and differ only by the extent of epidermal detachment and therefore severity. The term ‘epidermal necrolysis’ (EN) is used in this article to describe the spectrum of disease that includes SJS and TEN. Important advances in understanding the pathomechanism and treatment of EN have been made over the years. These include the recognition of human leucocyte antigen (HLA) associations (e.g. HLA‐B*1502 with carbamazepine‐induced TEN) and understanding of the pathogenic roles of drug‐specific cytotoxic T cells and granulysin. It was previously believed that widespread keratinocyte death in EN is predominantly mediated by soluble Fas‐ligand and that intravenous immunoglobulin therapy is useful in blocking this mechanism with resultant survival benefits. Further studies have since proven these theories to be incorrect. This short review describes the key advances in the terminology, classification, causality and treatment of EN, and identifies future priorities and challenges in the understanding and management of this condition.     

The association of HLA B*15:02 allele and Stevens–Johnson syndrome/toxic epidermal necrolysis induced by aromatic anticonvulsant drugs in a South Indian population

Background

The presence of HLA‐B*15:02 allele is considered a risk factor for development of Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in patients taking aromatic anticonvulsant drugs like carbamazepine and phenytoin. The genetic association is ethnicity specific. Testing for HLA‐B*15:02 allele is suggested as a prerequisite before starting carbamazepine in certain ethnic groups. There are only a few/no studies from south India on HLA association of SJS/TEN.

Aims

To identify any association between HLA‐B*15:02 allele and SJS/TEN induced by carbamazepine/phenytoin among native population.

Methods (including settings, design, and statistical analysis used)

A case–control study done in a tertiary care center at Kottayam in Kerala state of south India. Cases were 12 native patients who developed SJS/TEN owing to aromatic anticonvulsant drugs (phenytoin – 8; carbamazepine – 4), and controls were 11 persons tolerant to these drugs from unrelated families of the same ethnic group. HLA‐B typing was done by PCR SSP method.

Results

There was only one HLA‐B*15:02 carrier among cases and controls. He/she had SJS/TEN induced by carbamazepine.

Conclusions

Association of HLA‐B*15:02 with phenytoin‐induced SJS/TEN is rare in the population studied. The one limitation of the study was the small sample size.     

Diagnosis and management of Stevens-Johnson syndrome/toxic epidermal necrolysis

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare, immunologically mediated cutaneous adverse reaction characterized by mucous membrane and epidermal detachment, with a mortality ranging from 15% to 25%. Risk factors for the development of SJS/TEN include immune dysregulation, active malignancy, and genetic predisposition. Medications are the most common cause, particularly antimicrobials, antiepileptics, allopurinol, and nonsteroidal anti-inflammatory medications. Drug-specific CD8 T-cells and natural killer cells are thought to be the major inducers of keratinocyte apoptosis via release of soluble cytotoxic mediators, including Fas ligand, perforin/granzyme, tumor necrosis factor, and granulysin. When SJS/TEN is suspected clinically, appropriate therapy should be instituted without delay. All patients should be managed initially in an intensive care unit or burn unit under a multidisciplinary team of physicians experienced in the care of patients with SJS/TEN. Available data support the use of various pharmacologic agents to halt disease progression and improve outcomes, but no single drug has been found to be superior or beneficial for all patients. Future research should focus on developing a better understanding of the genetic susceptibility and immunopathophysiology of the disease, as well as novel diagnostic and therapeutic targets to improve patient outcomes.     

Genotype–phenotype association between HLA and carbamazepine-induced hypersensitivity reactions: Strength and clinical correlations

BackgroundIncreasing studies reported genetic susceptibility to drug hypersensitivity reactions, as exemplified by the HLA-A*31:01 and HLA-B*15:02 association with carbamazepine (CBZ)-induced hypersensitivity reactions, such as maculopapular exanthema (MPE), drug rash with eosinophilia and systemic symptoms (DRESS), and Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN).ObjectiveTo carry out a comprehensive analysis on the clinical spectrum and HLA genotype–phenotype correlations in CBZ-induced hypersensitivity reactions.MethodsWe analyzed the clinical information of 194 patients with CBZ hypersensitivity (51 MPE, 23 DRESS, 112 SJS/TEN, and 8 cases with other phenotypes), and 152 CBZ-tolerant controls. All are Han Chinese. We examined the HLA-A/HLA-B genotypes, gene dosage, and drug dosage effects.ResultsCBZ-SJS/TEN showed the strongest association with the HLA-B*15:02 allele (Pc = 5.8 × 10⁻⁴³; odds ratio (OR) (95% CI) = 97.6(42.0–226.8)), in which HLA-B*15:02 was identified in all patients (25/25) with SJS/TEN with >5% body surface area (BSA) skin detachment, but lost its 100% association (85.1%, 74/87) in SJS with <5% BSA detachment. In contrast, HLA-B*40:01 showed negative association with CBZ-induced SJS/TEN ((Pc = 8.3 × 10⁻⁵; OR (95% CI) = 0.22(0.1–0.4)). By comparison, CBZ-induced MPE/DRESS had no association with HLA-B*15:02, but linked to HLA-A*31:01 (Pc = 2.7 × 10⁻³; OR (95% CI) = 6.86(2.4–19.9), and HLA-B*51:01 (Pc = 0.01; OR (95% CI) = 4.56(2.0–10.5)). No gene dosage or CBZ dosage effects was observed.ConclusionThis study reported the different strength of HLA association with CBZ hypersensitivity in Han Chinese. With the increasing application of pharmacogenetic markers, the HLA genotype–phenotype correlations and the results of the test need to be carefully interpreted for CBZ-induced hypersensitivity reactions.     

Toxic epidermal necrolysis and Stevens-Johnson syndrome: soluble Fas ligand involvement in the pathomechanisms of these diseases

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are considered part of a spectrum of adverse cutaneous drug reactions showing severe and extensive skin detachment. TEN and SJS are morphologically characterized by active apoptotic keratinocyte cell death that results in the separation of the epidermis from the dermis. TEN is a life-threatening disease with a high mortality rate (20-30%). Although several therapies have been tried, there is no specific outstanding of generally accepted treatment for TEN at present. The pathogeneses of TEN and SJS have not yet been fully elucidated. We have demonstrated that high concentrations of soluble FasL (sFasL) are detected in TEN/SJS patients' serum samples and sFasL secreted by peripheral blood mononuclear cells interacts with the Fas expressed on diseased keratinocytes in TEN/SJS. Our data suggested sFasL is a prime candidate for therapeutic intervention, whereas a few recent papers have reported sFasL levels were not elevated in some TEN patients. An urgent review of the pathophysiology in TEN/SJS is needed to resolve this issue and to determine more effective treatment regimes.     

A multicentre study to determine the value and safety of drug patch tests for the three main classes of severe cutaneous adverse drug reactions

Background Drug patch tests (PTs) can reproduce delayed hypersensitivity to drugs and entail a moderate re‐exposure of patients to offending drugs. Objectives To determine the value of PTs for identifying the responsible drug in severe cutaneous adverse drug reactions (SCARs) such as acute generalized exanthematous pustulosis (AGEP), drug reaction with eosinophilia and systemic symptoms (DRESS) and Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). Methods In a multicentre study, PTs were conducted on patients referred for DRESS, AGEP or SJS/TEN within 1 year of their SCAR. All drugs administered in the 2 months prior to and the week following the onset of the SCAR were tested. Results Among the 134 patients included (48 male, 86 female; mean age 51·7 years), positive drug PTs were obtained for 24 different drugs. These included positive tests for 64% (46/72) of patients with DRESS, 58% (26/45) of those with AGEP and 24% (4/17) of those with SJS/TEN, with only one relapse of AGEP. The value of PTs depended on the type of drug and the type of SCAR (e.g. carbamazepine was positive in 11/13 DRESS cases but none of the five SJS/TEN cases). PTs were frequently positive for beta lactams (22 cases), pristinamycin (11 cases) and in DRESS with pump proton inhibitors (five cases), but were usually negative for allopurinol and salazopyrin. Of 18 patients with DRESS, eight had virus reactivation and positive PTs. In DRESS, multiple drug reactivity was frequent (18% of cases), with patients remaining sensitized many years later. Conclusions PTs are useful and safe for identifying agents inducing SCAR.     

Differential diagnosis of severe cutaneous drug eruptions

Adverse cutaneous reactions to drugs are frequent, mostly secondary to antibacterials, however, serious adverse cutaneous reactions are infrequent. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are a spectrum of the same disease. They are the more severe drug eruptions, with a mortality around 30% for TEN. The confusion between erythema multiforme major and SJS means that erythema multiforme major is the main differential diagnosis. Skin disorders involving desquamation, in particular after pustulosis, are also common differential diagnoses. Mechanical or autoimmune blistering are also potential misdiagnoses of TEN/SJS. Hypersensitivity Syndrome (HSS) or Drug Rash with Eosinophilia and Systemic Symptoms (DRESS) is a severe cutaneous drug reaction with often a long duration of eruption and serious other organ involvement. Exfoliative dermatitis, whether caused by psoriasis, dermatitis or lymphoma, can be thought of as a differential diagnosis of DRESS/HSS. Angio-immunoblastic lymphadenopathy, viral eruption and vasculitis are other differential diagnoses of DRESS/HSS. Prompt recognition of a severe drug reaction and withdrawal of the culprit drug is often the most important therapeutic action. Alternatively, a delay in starting a specific treatment for a disease misdiagnosed as a drug eruption could be deleterious.     

Severe flucloxacillin‐induced acute generalized exanthematous pustulosis (AGEP), with toxic epidermal necrolysis (TEN)‐like features: does overlap between AGEP and TEN exist? Clinical report and review of the literature

Acute generalized exanthematous pustulosis (AGEP) and Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) are rare but severe cutaneous adverse drug reactions. Especially in TEN, large areas of the skin and mucosae may become detached. Although AGEP and SJS/TEN are distinct entities with a different clinical picture, pathogenesis, prognosis and treatment, they may share some features, raising the hypothesis of overlap between both entities. We present a severe case of AGEP, caused by flucloxacillin, clinically presenting with TEN‐like features and pronounced systemic symptoms with haemodynamic and respiratory instability. Furthermore, we present a review of the literature on cases of AGEP with features resembling SJS/TEN or a supposed overlap with SJS/TEN.     

Drug rash with eosinophilia and systemic symptoms vs toxic epidermal necrolysis: the dilemma of classification

According to contemporary vernacular, when the cutaneous manifestations of drug rash with eosinophilia and systemic signs (DRESS) syndrome are those of Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN), the condition is defined as "DRESS syndrome with severe cutaneous reactions". In this article, we have presented arguments for and against including patients with skin lesions of the SJS/TEN syndromes who also have fever (practically all of the patients) and internal organ involvement (most of the patients) under the definition of DRESS syndrome. After weighing the arguments for and against this alteration of definition, we conclude that it makes more sense for patients with SJS/TEN to be classified as such and not be lumped together under the misleading label of DRESS syndrome.     

Schwere Arzneimittelreaktionen der Haut

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are severe drug-induced bullous skin reactions. They are rare, but often life-threatening and have a high mortality rate. Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction, but after the suspected drug is withdrawn, the skin heals rapidly and mortality is low. The clinical pattern, histology and inducing drugs differ substantially between AGEP and the SJS/TEN group.     

The role of prior corticosteroid use on the clinical course of Stevens-Johnson syndrome and toxic epidermal necrolysis: a case-control analysis of patients selected from the multinational EuroSCAR and RegiSCAR studies

Background Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are immunologically mediated, severe cutaneous adverse reactions involving cytotoxic T cells, natural killer cells and various mediators. In large studies, up to 15% of SJS/TEN occurred in patients with chronic corticosteroid use. It is unclear if this prior exposure to corticosteroids modified the disease course. Objectives To evaluate whether systemic corticosteroid usage prior to the onset of SJS/TEN modified the clinical course and outcome. If a disease‐modifying effect is present, information from such an analysis may have implications on the therapeutic use of corticosteroids in SJS/TEN. Methods This is a case–control study based on data collected in the EuroSCAR and RegiSCAR studies. Ninety‐two cases of SJS/TEN with exposure to corticosteroids prior to the onset of disease, and 321 randomly selected SJS/TEN patients without prior exposure were included. Primary outcomes included progression of disease, disease severity and mortality. A secondary analysis of latency between the beginning of drug use and the onset of disease, based on exposure to a single high‐risk drug, was also performed. Results On multivariate analysis, cases with prior exposure to corticosteroids had a longer progression of disease by 2·2 days [95% confidence interval (CI) 1·1–3·2]. The disease severity and mortality outcome were unaffected. In addition, there is evidence that corticosteroids delayed the onset of SJS/TEN in patients with exposure to high‐risk drugs by 7·1 days (CI ?0·2 to 14·5). Conclusions The prior use of corticosteroids prolonged the period of disease progression without influencing the disease severity or mortality. In addition, when SJS/TEN is preceded by use of a single high‐risk drug, the latency between the drug intake and the onset of SJS/TEN may also be increased. These findings suggest that corticosteroids have a mild impact on the course of SJS/TEN, and further studies are required to clarify any potential therapeutic effects.     

The life-threatening eruptions of immune checkpoint inhibitor therapy

Immune checkpoint inhibitors (ICPi) have emerged as a new frontier of cancer therapy. Although monoclonal antibodies to cytotoxic T-lymphocyte associated protein 4 (CTLA-4), programmed cell death 1 (PD-1), and programmed cell death ligand 1 (PD-L1) have revolutionized oncologic management, these agents may result in a spectrum of immune-related adverse events (irAE) of which dermatologic toxicities are among the most frequent. Prompt recognition and management of irAE is essential for dermatologists caring for the expanding population of cancer patients exposed to these drugs. Cutaneous toxicities range from mild cases to severe and life-threatening presentations that may cause significant morbidity and mortality. This review provides an overview of severe cutaneous adverse reactions (SCARs) that may develop during ICPi therapy, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP). In addition, immunobullous disorders, erythroderma, neutrophilic dermatoses, and cutaneous eruptions associated with systemic manifestations are discussed.