Some skin conditions may require intensive care treatment. Early diagnosis can be challenging but is crucial to adequate patient management and decision making, since appropriate treatment influences prognosis. The following skin conditions will be reviewed: severe cutaneous drug reactions (drug reaction with eosinophilia and systemic symptoms [DRESS], Stevens-Johnson syndrome/toxic epidermal necrolysis [SJS/TEN]), acute cutaneous graft versus host disease (aGvHD) following allogeneic stem cell transplantation, infectious diseases (staphylococcal scalded skin syndrome [SSSS], toxic shock-syndrome [TSS], necrotizing fasciitis) and vascular disease (acute infectious purpura fulminans). We focus on the course of the diseases, describing clinical presentation and differential diagnosis as well as diagnostic and therapeutic strategies.

Drug reaction with eosinophilia and systemic symptoms (DRESS), a severe cutaneous adverse reaction, represents a diagnostic and therapeutic challenge due to its varied, evolving clinical presentation, complex pathophysiology, and potential for severe systemic involvement. This article explores DRESS syndrome through 3 illustrative cases from diverse populations and with different background comorbidities. Cases highlight different challenges in DRESS care, including (1) the need for early diagnosis and severity scoring, (2) identification of offending drugs and risk stratification to consider a possible drug challenge, and (3) best practice management including long-term monitoring for emergent autoimmunity. Recent developments in our understanding of clinical spectrum of disease, genomic and nongenomic biomarkers, severity groupings, and pharmacological and longer-term management strategies are described. Critical gaps remain in several of these domains, particularly in vulnerable groups such as the immune-compromised. In the absence of robust evidence, we aim in this article to assist attending clinicians with current expert opinion in DRESS management. Finally, we highlight areas for further research needed to improve the clinical care and outcomes of DRESS.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis are fatal adverse skin reactions characterized by high fever, epidermal detachment, and mucositis. Selpercatinib is a highly selective inhibitor of tyrosine kinase, rearranged during transfection (RET), and is the first targeted therapy for solid tumors with RET gene alteration. The main adverse events of selpercatinib include hypertension, liver dysfunction, diarrhea, and QT prolongation on electrocardiograms. We present the case of 50-year-old male with medullary thyroid carcinoma who was treated with selpercatinib. On the 12th day of the treatment, he developed widespread erythema, which resulted in a referral to our department. Physical examination revealed disseminated erythematous macules, conjunctival congestion, and bloody crusting of the lips, and histopathological examination showed single-cell necrosis in epidermis. Based on these findings, he was diagnosed with SJS. After the discontinuation of selpercatinib and systemic administration of corticosteroids, his symptoms were improved. The patient showed positivity for selpercatinib in drug lymphocyte stimulation test, suggesting the diagnosis of SJS induced by selpercatinib. To the best of our knowledge, this is the first report of SJS caused by selpercatinib. We herein present and discuss this case to raise awareness.

There is no consensus regarding the treatment of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Supportive care remains the preferred approach internationally, while the efficacy of topical/systemic therapies is subject to controversy. We reviewed published guidelines and recommendations on SJS/TEN management and assessed supportive care involving topical and systemic therapies in a series of SJS patients. We included several specialty departments from different countries to determine the consensus in the management of SJS/TEN. We also included SJS patients and provided supportive care including silver nitrate at 0.5% sprayed on denuded areas, in conjunction with a single dose of subcutaneous etanercept. Based on our literature review and experience, we propose a management algorithm for SJS/TEN. Our review confirmed the importance of supportive care, including specific topical and systemic treatments, for SJS/TEN. Systemic corticotherapy, cyclosporine A, intravenous immunoglobulin, tumor necrosis factor-alpha (TNF-α) blockers, or combinations are subject to controversies. In our pilot series of seven adult patients with SJS, we obtained good clinical results within 1 week, with mucosal and skin clearance at Week 2, along with a good safety profile. This was achieved by spraying topical silver nitrate at a concentration of 0.5% on denuded areas, following a single dose of etanercept. This consensus led to the recommendation of a combination of supportive care along with several possible topical and systemic therapies for SJS/TEN. Corticosteroids, immunoglobulins, cyclosporine A, and TNF-alpha blockers were used in our centers alone or in combination, with good results associated with 0.5% topical silver nitrate. In our series of SJS patients, silver nitrate at 0.5% associated with etanercept showed a good response.

Some skin conditions may require intensive care treatment. Early diagnosis can be challenging but is crucial to adequate patient management and decision making, since appropriate treatment influences prognosis. The following skin conditions will be reviewed: severe cutaneous drug reactions (drug reaction with eosinophilia and systemic symptoms [DRESS], Stevens-Johnson syndrome/toxic epidermal necrolysis [SJS/TEN]), acute cutaneous graft versus host disease (aGvHD) following allogeneic stem cell transplantation, infectious diseases (staphylococcal scalded skin syndrome [SSSS], toxic shock-syndrome [TSS], necrotizing fasciitis) and vascular disease (acute infectious purpura fulminans). We focus on the course of the diseases, describing clinical presentation and differential diagnosis as well as diagnostic and therapeutic strategies.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening cutaneous reactions often triggered by medications. While the involvement of CD8+ T cells causing keratinocyte death is well recognized, the contribution of neural elements to the persistent skin inflammation has been largely overlooked.

We investigated the potential neuroimmune regulation in SJS/TEN.

Unbiased single-cell RNA sequencing and flow cytometry were performed using circulating CD8+ T cells from healthy controls and patients with SJS/TEN. ELISA and LEGENDplex assays were respectively used to detect neuropeptides and inflammatory mediators. Skin tissues were examined by immunofluorescence staining for neuropeptide-associated nerves and cytokine receptors. Calcium imaging, Smart-seq, and a 3-D skin model were used for cultured human CD8+ T cells.

Unbiased RNA sequencing revealed an upregulation of the receptor for neuropeptide calcitonin gene-related peptide (CGRP), known as RAMP1, in effector CD8+ T cells in SJS/TEN. Increased CGRP+ nerve fibers and CGRP levels, along with upregulated IL-15R and IL-18R on CD8+ T cells, were displayed in the affected skin of SJS/TEN. The CGRP-RAMP1 axis was necessary and sufficient to enhance receptors for IL-15 and IL-18 and cytotoxic activities in CD8+ T cells, ultimately resulting in keratinocyte apoptosis. Calcium influx was detected in CGRP-stimulated CD8+ T cells. HCN2, a hyperpolarization-activated cation channel, was required for this process and the subsequent cytotoxic effects.

Our study highlights the role of neural elements in regulating CD8+ T-cell-mediated inflammatory responses and provides new potential translational targets to improve the outcomes of severe cutaneous drug reactions.

Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), shows superior lung cancer treatment efficacy. However, osimertinib-induced severe hypersensitivity, including Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN), is frequently observed in Asian populations and hinders cancer treatment.

We investigated the genetic HLA predisposition and immune pathomechanism of osimertinib-induced hypersensitivity.

We enrolled 17 patients with osimertinib-induced delayed hypersensitivity (seven with severe SJS/TEN and 10 with mild maculopapular exanthema), 98 osimertinib-tolerant subjects, and 2,123 general population controls. We performed HLA genotyping, drug-induced lymphocyte activation test, and surface plasmon resonance assay.

HLA-B∗51:02 was present in 83.3% of osimertinib-induced SJS/TEN patients but in only 3.3% of the general population controls (P = 2.8 × 10-7; corrected P = 6.9 × 10-6; odds ratio [OR] = 146), and 0% of osimertinib-tolerant controls (P = 6.5 × 10-8; corrected P = 1.6 × 10-6; OR = 707). The association of HLA-B∗51:01 and HLA-A∗24:02 with osimertinib-induced maculopapular exanthema patients, rather than with osimertinib-tolerant subjects (P = .002, OR = 15.7 for HLA-B∗51:01; and P = .003, OR = 9.5 for HLA-A∗24:02), was identified as a phenotype-specific association. Granulysin, the SJS/TEN-specific cytotoxic protein, was significantly higher in plasma of SJS/TEN patients (39.8 ± 4.5 ng/mL; P < .001) and in in vitro lymphocyte activation test (sensitivity = 83.3%; P < .01) compared with tolerant controls. Patients with osimertinib-induced hypersensitivity appeared to tolerate alternative EGFR-TKIs. Surface plasmon resonance results also confirmed that HLA-B∗51:02 protein has a higher binding affinity for osimertinib and lower or no affinity for other EGFR-TKIs.

HLA-B∗51:02 frequently occurs in Asian populations and is strongly associated with osimertinib-induced SJS/TEN. Our findings suggest HLA-B∗51:02 screening as a preemptive test to reduce osimertinib-induced severe hypersensitivity.

Immune checkpoint inhibitors (ICI) represent new anticancer agents and have been used worldwide. However, ICI can potentially induce life-threatening severe cutaneous adverse reaction (SCAR), such as Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), hindering continuous ICI therapy. We examine 6 cohorts including 25 ICI-induced SJS/TEN patients and conduct single-cell RNA sequencing (scRNA-seq) analysis, which shows overexpression of macrophage-derived CXCL10 that recruits CXCR3+ cytotoxic T lymphocytes (CTL) in blister cells from ICI-SJS/TEN skin lesions. ScRNA expression profiles and ex vivo blocking studies further identify TNF signaling as a pathway responsible for macrophage-derived CXCL10 and CTL activation. Based on the trajectory analysis, ICI-activated T cells from whole blood are proposed to serve as the initial cells involved in inflammation, that lead to monocytes differentiating into macrophages and increasing their susceptibility to migrate to the lesion sites. Compared with systemic corticosteroids treatment, ICI-induced SJS/TEN patients treated with biologic TNF blockade showed a significantly rapid recovery and no recurrence of SCAR with continuous ICI therapy. Our findings identify that macrophage-eliciting CTL contribute to the pathogenesis of ICI-induced epidermal necrolysis and provide potential therapeutic targets for the management and prevention of SCAR induced by ICI therapy.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) represent a severe spectrum of rare mucocutaneous reactions that are primarily drug-induced and characterized by significant morbidity and mortality. These conditions manifest in extensive skin detachment, distinguishing them from other generalized skin eruptions. The rarity and severity of SJS/TEN underscore the importance of accurate diagnostic criteria and effective treatments, which are currently lacking consensus. This review proposes new diagnostic criteria to improve specificity and global applicability. Recent advances in understanding the immunopathogenesis of SJS/TEN are explored, emphasizing the role of drug-specific T-cell responses and human leucocyte antigen polymorphisms in disease onset. The review also addresses current therapeutic approaches, including controversies surrounding the use of immunosuppressive agents and the emerging role of tumour necrosis factor-α inhibitors. Novel therapeutic strategies targeting specific pathogenic mechanisms, such as necroptosis and specific immune cell pathways, are discussed. Furthermore, the development of new drugs based on these insights, including targeted monoclonal antibodies and inhibitors, are examined. The review concludes by advocating for more robust and coordinated efforts across multidisciplinary medical fields to develop effective treatments and diagnostic tools for SJS/TEN, with the aim of improving patient outcomes and understanding the disease and its mechanisms.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are the most severe cutaneous adverse reactions that are typically drug-induced in adults. Both SJS and TEN have high morbidity and mortality rates. SJS/TEN imposes clinical challenges for physicians managing patients suffering from this condition, both because it is rare and because it is a rapidly progressing systemic disease with severe cutaneous, mucosal, and systemic manifestations. Although many cases of SJS/TEN have been reported in the literature, there is no consensus regarding diagnostic criteria or treatment. Significant progress has been made in understanding its genetic predisposition and pathogenesis. This review is intended to provide physicians with a comprehensive but practical SJS/TEN roadmap to guide diagnosis and management. We review data on pathogenesis, reported precipitating factors, presentation, diagnosis, and management SJS/TEN focusing on what is new over the last 5 years.

To investigate the incidence and prognostic factors of ocular sequelae in Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) cases arising between 2016 and 2018 in Japan, and compare the findings with those presented in the previous 2005-2007 survey.

Retrospective, national trend survey.

Dermatologic case report forms (CRFs) (d-CRFs) were sent to 257 institutions that treated at least 1 SJS/TEN case, and 508 CRFs were collected from 160 institutions. Ophthalmologic CRFs (o-CRFs) regarding patient demographic data, onset date, ocular findings (first appearance, day of worst severity, and final follow-up), topical treatment (betamethasone), outcome (survival or death), and ocular sequelae (visual disturbance, eye dryness) were sent to the ophthalmologists in those 160 institutions. The results of this survey were then compared with that of the previous 2005-2007 survey.

A total of 240 cases (SJS/TEN: 132/108) were included. The incidence of ocular sequelae incidence was 14.0%, a significant decrease from the 39.2% in the previous survey (SJS/TEN: 87/48). In 197 (82.1%) of the cases, systemic treatment was initiated within 3 days after admission, an increase compared to the previous survey (ie, treatment initiated in 82 [60.7%] of 135 cases). Of the 85 cases with an Acute Ocular Severity Score of 2 and 3, 62 (72.9%) received corticosteroid pulse therapy and 73 (85.9%) received 0.1% betamethasone therapy; an increase compared to the 60.0% and 70.8%, respectively, in the previous survey. Ocular-sequelae-associated risk factors included Acute Ocular Severity Score (P < .001) and specific year in the survey (P < .001).

The ophthalmologic prognosis of SJS/TEN has dramatically improved via early diagnosis, rapid assessment of acute ocular severity, and early treatment.

Epidermal necrolysis (EN), comprising Stevens-Johnson syndrome and toxic EN, is a rare and severe blistering reaction, mainly induced by drugs. Differences between paediatric and adult patients regarding incidence, causes and outcomes have been discussed but are based on a limited number of patients from small case series.

To directly compare the incidence, cause and prognosis of adult and paediatric EN.

We used data from the French Health System Database (1 January 2013-31 December 2022). We identified adult and paediatric patients hospitalized for EN using the International Classification of Diseases, 10th Revision codes combined with validated algorithms. Outcomes were the incidence of EN; the presence of a suspected drug before EN onset (defined as a new drug dispensation from 5 to 56 days prehospitalization); and in-hospital mortality. To estimate the association between paediatric EN and the presence of a suspect drug, we computed a multivariable logistic regression with odd ratios (ORs). To estimate the association with mortality, we computed a multivariable Cox proportional hazard ratio (HR) model.

A total of 1440 patients [799 (55.5%) female] with EN were included, comprising 219 children and 1221 adults. Among children, the incidence of EN was 1.5 cases [95% confidence interval (CI) 1.3-1.7] per 1 million person-years vs. 2.6 cases (95% CI 2.5-2.7) in adults. Moreover, children had less chance of being given a culprit drug before the onset of EN [n = 93/219 (42.5%) vs. n = 829/1221 (67.9%)], with an adjusted OR of 0.43 (95% CI 0.32-0.59; P < 0.001), together with a better prognosis: the mortality rate in paediatric patients was 1.4% (95% CI 0.4-3.7) vs. 19.4% (95% CI 17.3-21.7) in adults. The adjusted HR for in-hospital mortality in children was 0.12 (95% CI 0.04-0.38; P < 0.001).

Paediatric EN appears to be rarer, with less chance of being caused by drugs and has a better prognosis than adult EN. These results suggest the existence of different underlying pathophysiological mechanisms and clinical particularities between adult and paediatric patients with EN.

Erythema multiforme (EM) is considered a hypersensitivity reaction associated with drugs and infections, and remains underestimated due to the lack of precise classification and diagnostic criteria. The aim of this study was to evaluate the triggering factors and clinical manifestations of EM and to present our experience in the diagnosis and management of this disorder.

All patient records were reviewed, and records of patients admitted, diagnosed, and treated with EM were retrieved. Data on age, gender, medical history, triggering factor(s), clinical form, mucosal/cutaneous involvement, affected oral site(s), recurrence, and treatment were collected. The data were analyzed statistically at a significance level set at P < 0.05.

A total of 36 EM patients were studied. The triggering factor was identified as infection in 25 %, drugs in 16.7 %, infections and drugs in 41.7 %, and none in 16.7 % of the 36 EM patients. EM minor was diagnosed in 77.8 % of the patients. Labial mucosa (86.1 %) was the most commonly affected oral site. Most patients were treated with topical steroids (25 %). No significant differences were detected between demographic and clinical characteristics with regards to gender, triggering factor, and the number of affected oral sites (P > 0.05).

The results of this study, based on the data from 36 EM patients with oral involvement treated at our clinic, can guide dentists in this regard and may be considered as an epidemiological source for the region.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are rare, predominantly drug-induced, acute, life-threatening diseases of skin and mucosae. SJS and TEN are nowadays considered variants of one disease entity with varying degrees of severity called epidermal necrolysis (EN). EN is associated with high morbidity and mortality and constitutes a major disease burden for affected patients. The guideline "Diagnosis and treatment of epidermal necrolysis (Stevens-Johnson syndrome and toxic epidermal necrolysis)" was developed under systematic consideration of existing scientific literature and in a formal consensus process according to regulations issued by the Association of Scientific Medical Societies in Germany (AWMF) to establish an evidence-based framework to support clinical decision-making. The interdisciplinary guideline commission consisted of representatives from various specialist societies and patient representatives. The guideline is aimed at specialists in the fields of dermatology, ophthalmology, plastic surgery, intensive care, and pediatrics in hospitals and offices, as well as other medical speciallved in the diagnosis and treatment of EN. The guideline is also aimed at patients, their relatives, insurance funds, and policymakers. This first part focuses on the diagnostic aspects, the initial management as well as the immunomodulating systemic therapy.

Patient registries are a mechanism for collecting data on allergic and immunologic diseases that provide important information on epidemiology and outcomes that can ultimately improve patient care. Key criteria for establishing effective registries include the use of a clearly defined purpose, identifying the target population and ensuring consistent data collection. Registries in allergic diseases include those for diseases such as inborn errors of immunity (IEI), food allergy, asthma and anaphylaxis, pharmacological interventions in vulnerable populations, and adverse effects of pharmacologic interventions including hypersensitivity reactions to drugs and vaccines. Important insights gained from patient registries in our field include contributions in phenotype and outcomes in IEI, the risk for adverse reactions in food-allergic patients in multiple settings, the benefits and risk of biologic medications for asthma during pregnancy, vaccine safety, and the categorization and genetic determination of risk for severe cutaneous adverse reactions to medications. Impediments to the development of clinically meaningful patient registries include the lack of funding resources for registry establishment and the quality, quantity, and consistency of available data. Despite these drawbacks, high-quality and successful registries are invaluable in informing clinical practice and improving outcomes in patients with allergic and immunological diseases.

Erythema multiforme (EM) is a delayed, cell-mediated cutaneous disease with varying clinical manifestations. It is most commonly associated with infections but can also be associated with medications, vaccines, and autoimmune diseases. Non-steroidal anti-inflammatory Drugs (NSAIDs) are commonly used analgesics that have rare associations with EM and pancytopenia. These adverse reactions to NSAIDs can obscure definitive diagnosis due to their rarity. We present a case where an elderly female patient taking 600mg of ibuprofen up to four times a day for shoulder bursitis developed EM and pancytopenia. In this case, a 75-year-old female with a medical history of atrial fibrillation, essential hypertension, non-insulin-dependent type 2 diabetes mellitus, and ischemic stroke with residual right-sided visual impairment presented to our Emergency Department in 2023 with neck swelling, skin rash, and ulceration of the oral cavity. She reported a generalized, targetoid body rash that occurred 15 days after she started taking ibuprofen regularly for left shoulder bursitis. No other medications were started before, after, or during this time period. CBC on admission was remarkable for a white blood cell count of 1.5x109/L, hemoglobin of 6.5 g/dL, and platelet count <10x109/L, consistent with pancytopenia. Ibuprofen was discontinued, and the patient was treated supportively with analgesia and packed red blood cell transfusions. Testing for HIV, antinuclear antibodies (ANA) panel, Hepatitis panel, and copper and zinc levels were negative. A biopsy of a targetoid lesion on the skin showed changes consistent with EM. Esophagogastroduodenoscopy revealed no actively bleeding lesions or ulcers in the stomach mucosa. The patient's blood counts eventually recovered with supportive treatment, and symptomatology improved. The patient was discharged six days after admission. Healthcare professionals should be aware of rare hematologic and immunologic side effects of NSAIDs, which may often be overlooked and misdiagnosed. More studies are needed to build on our wealth of knowledge regarding the etiology and management of EM, Steven Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN).

Amoxicillin (AMX) is among the most prescribed and the best tolerated antimicrobials worldwide. However, it can occasionally trigger severe cutaneous adverse reactions (SCAR) with a significant morbidity and mortality. The genetic factors that may be relevant to AMX-induced SCAR (AMX-SCAR) remain unclear. Identification of the genetic risk factor may prevent patients from the risk of AMX exposure and resume therapy with other falsely implicated drugs.

Four patients with AMX-SCAR, 1,000 population control and 100 AMX-tolerant individuals were enrolled in this study. Both exome-wide and HLA-based association studies were conducted. Molecular docking analysis was employed to simulate the interactions between AMX and risk HLA proteins.

Compared with AMX-tolerant controls, a significant association of HLA-B*15:01 with AMX-SCAR was validated [odds ratio (OR) = 22.9, 95% confidence interval (CI): 1.68-1275.67; p = 7.34 × 10-3]. Moreover, 75% carriers of HLA-B*15:01 in four patients with AMX-SCAR, and the carrier frequency of 10.7% in 1,000 control individuals and 11.0% in 100 AMX-tolerant controls, respectively. Within HLA-B protein, the S140 present in all cases and demonstrated the strongest association with AMX-SCAR [OR = 53.5, p = 5.18 × 10-4]. Molecular docking results also confirmed the interaction between AMX and S140 of the HLA-B protein, thus eliminating the false-positive results during in association analysis.

Our findings suggest that genetic susceptibility may be involved in the development of AMX-SCAR in Han Chinese. However, whether the HLA-B variants observed in this study can be used as an effective genetic marker of AMX-induced SCAR still needs to be further explored in larger cohort studies and other ethnic populations.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and potentially life-threatening mucocutaneous blistering diseases that clinically can resemble autoimmune bullous diseases. Moreover, it has been shown that autoantibodies against epidermal proteins are present in SJS/TEN.

To establish the presence of antibodies against desmosomal and hemidesmosomal proteins in confirmed SJS/TEN patients.

Serum of SJS/TEN patients diagnosed based on clinical criteria, e.g., epidermal detachment with erosions and severe mucosal lesions, (suspicion of) a culprit drug, and matching histologic results was evaluated by various techniques, e.g., indirect immunofluorescence on monkey esophagus, salt split skin and rat bladder, immunoblotting (IB) and immunoprecipitation (IP), ELISAs against desmogleins and BP180, keratinocyte footprint assay, and keratinocyte binding assay.

A total of 28 patients were included in this study, 15 men and 13 women with a mean age of 56 years. In most patients, none of the serological tests were positive. In two patients, an elevated DSG3 titer was found suspicious for pemphigus vulgaris. Three patients had elevated NC16a titers, suggesting bullous pemphigoid. However, in all these patients, no other tests were positive and in these patients, the biopsy for direct immunofluorescence showed no evidence for an autoimmune bullous disease. Three patients showed reactivity against rat bladder rat bladder; these were, however, completely negative for A2ML1, envoplakin, and periplakin in the IB as well as the IP.

Serological analysis for desmosomal and hemidesmosomal antibodies is reliable to rule an autoimmune bullous disease in patients with suspected SJS/TEN. However, one should not rely on one single test method since false positive results can occur. Moreover, this study also makes it less plausible that antibodies against desmosomal and/or hemidesmosomal components are involved in the pathogenesis of SJS/TEN.

Drug-induced hypersensitivity syndrome, also known as drug reaction with eosinophilia and systemic symptoms, is a severe cutaneous adverse reaction characterized by an exanthem, fever, and hematologic and visceral organ involvement. The differential diagnosis includes other cutaneous adverse reactions, infections, inflammatory and autoimmune diseases, and neoplastic disorders. Three sets of diagnostic criteria have been proposed; however, consensus is lacking. The cornerstone of management is immediate discontinuation of the suspected drug culprit. Systemic corticosteroids remain first-line therapy, but the literature on steroid-sparing agents is expanding. Longitudinal evaluation for sequelae is recommended. Adjunctive tests for risk stratification and drug culprit identification remain under investigation. Part II of this continuing medical education activity begins by exploring the differential diagnosis and diagnosis of drug-induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms and concludes with an evidence-based overview of evaluation and treatment.

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.

Anticancer drugs have revolutionized tumor therapy, with cutaneous toxicities such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) being common immune-related adverse events. The debate over the efficacy of systemic corticosteroids in treating these conditions persists, while tumor necrosis factor (TNF)-alpha inhibitors show promise. This study aims to evaluate the effectiveness and safety of combination therapy involving the TNF-α inhibitor adalimumab for SJS/TEN induced by anticancer drugs.

A literature review of SJS/TEN cases induced by anticancer drugs from 1992 to 2023 was conducted, alongside an analysis of patients admitted to the First Affiliated Hospital of Fujian Medical University during the same period. Clinical characteristics, skin healing time, mortality, and adverse events were evaluated in two treatment groups: SJS/TEN patients treated with targeted anticancer therapies and immunotherapies.

Among the 27 patients studied (18 with SJS or SJS-TEN overlapping and 9 with TEN), combination therapy with adalimumab significantly reduced mucocutaneous reepithelization time and healing duration compared to corticosteroid monotherapy. Patients receiving adalimumab combined with corticosteroids had lower actual mortality rates than those on corticosteroid monotherapy. The combination therapy also showed a trend towards reducing standardized mortality rates based on the Score of Toxic Epidermal Necrolysis (SCORTEN).

The findings suggest that adalimumab in combination with corticosteroids provides significant clinical benefits and is safer than corticosteroids alone for treating SJS/TEN induced by targeted anticancer therapies and immunotherapies. This study contributes valuable insights into potential treatment strategies for severe cutaneous adverse reactions to anticancer drugs, highlighting the importance of exploring alternative therapies such as TNF-α inhibitors in managing these conditions effectively.

Since the 2002 SCAR study, erythema multiforme (EM), a post-infectious disease, has been distinguished from Stevens-Johnson syndrome (SJS), drug-induced. Nevertheless, EM cases are still reported in the French pharmacovigilance database (FPDB).

To describe EM reported in the FPDB and to compare the quality and the characteristics of the reports.

This retrospective observational study selected all EM cases reported in the FPDB over two periods: period 1 (P1, 2008-2009) and period 2 (P2, 2018-2019). Inclusion criteria were 1) a diagnosis of clinically typical EM and/or validated by a dermatologist; 2) a reported date of onset of the reaction; and 3) a precise chronology of drug exposure. Cases were classified confirmed EM (typical acral target lesions and/or validation by a dermatologist) and possible EM (not-otherwise-specified target lesions, isolated mucosal involvement, doubtful with SJS). We concluded possible drug-induced EM when EM was confirmed, with onset ranging from 5 to 28 days without an alternative cause.

Among 182 selected reports, 140 (77%) were analyzed. Of these, 67 (48%) presented a more likely alternative diagnosis than EM. Of the 73 reports of EM cases finally included (P1, n=41; P2, n=32), 36 (49%) had a probable non-drug cause and 28 (38%) were associated with only drugs with an onset time ≤4 days and/or ≥29 days. Possible drug-induced EM was retained in 9 cases (6% of evaluable reports). Etiological work-up was more often performed in period 2 than 1 (53.1% vs 29.3%, P=0.04), and the time to onset from 5 to 28 days was more frequent in period 2 (59.2% vs 40%, P=0.04).

This study suggests that possible drug-induced EM is rare. Many reports describe "polymorphic" rashes inappropriately concluded as EM or post-infectious EM with unsuitable drug accountability subject to protopathic bias.

The HLA-B*1502 allele is strongly associated with carbamazepine (CBZ)-induced Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) in the Han Chinese population. This study investigated the impact of HLA-B*1502 screening on CBZ utilization and rates of severe cutaneous allergic reactions (SCARs) and SJS/TEN over time in Taiwan, where screening for HLA-B*1502 genotyping before prescribing CBZ was reimbursed in June 2010.

Using the Taiwan National Health Insurance Research Database, we analyzed 13 277 457 episodes of seeking treatment for epilepsy or neuralgia between 2000 and 2017. Episodes were categorized into quarters based on treatment time. Propensity score-based stabilized weighting (PSSW) ensured well-balanced covariates. The difference in 3-month SCAR and SJS/TEN rates between phase 2 (2011-2017) and phase 1 (2000-2009) was examined using a one-sample Z-test. Pearson correlation coefficients assessed the association between screening rate, the number of CBZ users and nonusers, and SCAR and SJS/TEN rates after HLA-B*1502 genotyping.

CBZ prescriptions reduced from 7% (2000-2003) to 6% (2004-2010) and 4% (2011-2017). The screening rates of CBZ nonusers and CBZ users increased from 0%, .5% in 2011 to .8%, 16% in 2017, respectively. After PSSW, the mean 3-month SCAR incidence rates (per 10 000 episodes) significantly decreased from phase 1 to phase 2 for CBZ users (6.91 vs. 3.09, p < .0001) and nonusers (1.96 vs. 1.65, p < .0001). SJS/TEN incidence rates (per 10 000 episodes) significantly decreased from phase 1 to phase 2 for CBZ users (2.94 vs. 1.93, p < .0001) but not for nonusers (.71 vs. .74, p = .1492). In phase 2, SCAR incidence rates were significantly and negatively correlated with the screening rate for both CBZ users (r = -.38, p = .0342) and nonusers (r = -.80, p < .001). No significant correlation was found between SJS/TEN incidence rates and screening rates.

Recognizing HLA-B*1502 allele and avoiding CBZ therapy in HLA-B*1502-positive patients is critical for preventing CBZ-induced severe adverse events.

To clarify the importance of administering topical steroids for the treatment of Stevens-Johnson syndrome (SJS) / toxic epidermal necrolysis (TEN) with ocular involvement in the acute phase.

Retrospective case series.

Using the medical records of acute SJS/TEN patients treated at the Kyoto Prefectural University of Medicine Hospital, Kyoto, Japan, between July 2006 and July 2017, the ocular findings, topical steroid dosage, systemic steroid dosage, and ocular sequelae were retrospectively examined. The level of cytokines in tear fluid and serum samples was also analyzed.

This study involved 13 cases. In 10 cases in whom the clinical courses were recorded before the start of steroid therapy, the mean acute ocular severity score (AOSS: 3 = very severe; 2 = severe; 1 = mild; 0 = none) was 2.8 ± 0.4 points in the severest phase. The mean systemic steroid dose after steroid pulse therapy was 694 ± 386 mg and the mean topical steroid (0.1% betamethasone eye drop and ointment) dose was 13.4 ± 3.3 times daily in the severest phase. Analysis of cytokine levels of 4 cases showed that a cytokine storm occurred in the tear fluid after the steroid pulse therapy. At final follow-up, 16 eyes of 8 patients had a logMAR visual acuity of ≤0, and no serious ocular sequelae were observed.

In patients with SJS/TEN, ocular surface inflammation remains strong even after systemic inflammation has improved post steroid pulse therapy, thus suggesting that both systemic and topical steroid therapy should be administered appropriately.

Pethidine is an opioid derivative typically used to treat moderate-to-severe pain. It has a good analgesic effect and is considered safe, although with adverse effects such as nausea, depression, vomiting, respiratory depression, and toxicity. We discuss the case of a 43-year-old female patient who received intravenous pethidine and developed skin necrosis in multiple areas of the body as a complication and how it was managed. This is the first report in the literature discussing skin necrosis after intravenous pethidine.

Misoprostol, a synthetic prostaglandin E1 analog, is currently used for medical termination of pregnancy. In the summary of the product characteristics of different market authorization holders of misoprostol tablets, approved by major regulators, serious mucocutaneous reactions, including toxic epidermal necrolysis are not documented as adverse effects. We are now reporting an unusual case of toxic epidermal necrolysis following the use of misoprostol 200 mcg tablets prescribed for termination of a pregnancy. A 25-year-old grand multipara woman from the Gash-Barka region of Eritrea visited Tesseney hospital with a history of amenorrhea that lasted for four months. She was admitted as a case of missed abortion for medical termination of pregnancy. Following three doses of misoprostol 200 mcg tablet the patient developed toxic epidermal necrolysis. Except misoprostol, no other possible alternatives that could explain the condition were identified. Accordingly, the adverse effect was judged to be possibly related to misoprostol. The patient recovered after four weeks of treatment without sequelae. Toxic epidermal necrolysis could, therefore, be a possible adverse effect of misoprostol that needs to be further investigated with better epidemiological studies.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are severe cutaneous adverse reactions, and patients with SJS/TEN frequently require intensive care. However, there is limited evidence on the clinical outcomes of immunomodulating therapy, including plasmapheresis and intravenous immunoglobulin (IVIG) in patients with SJS/TEN.

To compare clinical outcomes of patients with SJS/TEN who were treated with plasmapheresis first vs IVIG first after ineffective systemic corticosteroid therapy.

This retrospective cohort study used data from a national administrative claims database in Japan that included more than 1200 hospitals and was conducted from July 2010 to March 2019. Inpatients with SJS/TEN who received plasmapheresis and/or IVIG therapy after initiation of at least 1000 mg/d of methylprednisolone equivalent systemic corticosteroid therapy within 3 days of hospitalization were included. Data were analyzed from October 2020 to May 2021.

Patients who received IVIG or plasmapheresis therapy within 5 days after initiation of systemic corticosteroid therapy were included in the IVIG- and plasmapheresis-first groups, respectively.

In-hospital mortality, length of hospital stay, and medical costs.

Of 1215 patients with SJS/TEN who had received at least 1000 mg/d of methylprednisolone equivalent within 3 days of hospitalization, 53 and 213 patients (mean [SD] age, 56.7 [20.2] years; 152 [57.1%] women) were included in the plasmapheresis- and IVIG-first groups, respectively. Propensity-score overlap weighting showed no significant difference in inpatient mortality rates between the plasmapheresis- and IVIG-first groups (18.3% vs 19.5%; odds ratio, 0.93; 95% CI, 0.38-2.23; P = .86). Compared with the IVIG-first group, the plasmapheresis-first group had a longer hospital stay (45.3 vs 32.8 days; difference, 12.5 days; 95% CI, 0.4-24.5 d; P = .04) and higher medical costs (US $34 262 vs $23 054; difference, US $11 207; 95% CI, $2789-$19 626; P = .009).

This nationwide retrospective cohort study found no significant benefit to administering plasmapheresis therapy first instead of IVIG first after ineffective systemic corticosteroid treatment in patients with SJS/TEN. However, medical costs and length of hospital stay were greater for the plasmapheresis-first group.

Cutaneous manifestations resembling Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) have been reported in patients with acute graft-versus-host disease (aGVHD); however, the clinicopathological characteristics of SJS/TEN-like aGVHD remain unexplored.

To investigate the clinicopathology, complications, and outcomes of patients with SJS/TEN-like aGVHD.

We analyzed a multicenter cohort of patients with aGVHD between 2000 and 2021.

We analyzed 31 patients with aGVHD, including SJS/TEN-like (n = 15) and non-SJS/TEN-like (n = 16). Patients with SJS/TEN-like aGVHD had significantly more extensive erythema and skin detachment/mucositis. SJS/TEN-like aGVHD was significantly associated with higher aGVHD grading and systemic complications, including pancytopenia, leukopenia, anemia, severe thrombocytopenia, coagulation abnormality, hepatitis, diarrhea, renal dysfunction, and bacteremia. A significantly lower hemoglobin/red cell distribution width ratio was identified in SJS/TEN-like aGVHD. Histopathology showed significant severe dyskeratosis and interface change. Patients with SJS/TEN-like aGVHD had lower 2-month survival rates and 5.35-fold higher 5-year mortality rates than those with non-SJS/TEN-like aGVHD. Total mortality rates of patients with SJS/TEN-like aGVHD reached 80% during follow-up; sepsis predominated the causes of death.

Retrospective, nonrandomized study with a small sample size.

SJS/TEN-like aGVHD is associated with multiple systemic complications and high mortality. Early recognition, differential diagnosis from drug-induced-SJS/TEN, and appropriate treatment are critical.

Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS/TEN) are rare but severe cutaneous adverse drug reactions. Certain human leukocyte antigen (HLA) types have been associated with SJS/TEN onset, e.g., HLA-B^∗58:01 with allopurinol-induced SJS/TEN, but HLA typing is time-consuming and expensive; thus, it is not commonly used in clinical situations. In the previous work, we demonstrated that the single-nucleotide polymorphisms (SNP) rs9263726 was in absolute linkage disequilibrium with HLA-B^∗58:01 in the Japanese population, and can be used as a surrogate marker for the HLA. Here, we developed a new genotyping method for the surrogate SNP using the single-stranded tag hybridization chromatographic printed-array strip (STH-PAS) technique and performed an analytical validation. The results of genotyping rs9263726 using STH-PAS correlated well with those obtained using the TaqMan SNP Genotyping Assay for 15 HLA-B^∗58:01-positive and 13 HLA-B^∗58:01-negative patients (analytical sensitivity and specificity were both 100%). Additionally, at least 1.11 ng of genomic DNA was sufficient to digitally and manually detect positive signals on the strip. Robustness studies showed that the annealing temperature (66 °C) was the most important condition related to reliable results. Collectively, we developed an STH-PAS method that can rapidly and easily detect rs9263726 for predicting SJS/TEN onset.

Severe cutaneous drug reactions also occur in children and range from reactions with blister forming of skin and mucosa to extensive exanthems with altered differential blood count and involvement of internal organs. The first group includes Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), which are considered as one disease entity with different degrees of severity and are also referred to as "epidermal" or "epithelial necrolysis" (EN). The group of drug reactions with primarily systemic alterations is represented by a condition known as drug reaction with eosinophilia and systemic symptoms (DRESS).Although EN is generally considered as a drug reaction, a causative agent can only be identified in about 50% of all pediatric cases. Once a clear diagnosis is established, specific treatment measures should be carried out, whereby discontinuation of the causative agent plays a decisive role in drug-induced cases. In order to be able to identify and discontinue the drug responsible, a detailed medication history must be obtained. Certain antiepileptic drugs, sulfonamides and sulfasalazine are among the most frequent triggers of EN and DRESS in children. Supportive therapy including appropriate topical treatment, pain management and ophthalmological consultations are of utmost importance in EN but a short-term immunomodulating treatment with cyclosporine A has been shown to be helpful. In contrast, in DRESS middle to long-term systemic treatment with glucocorticosteroids is recommended.

Drug induced erythema multiforme (EM) is a rare clinical entity which majorly involves the oral cavity. It commonly occurs due to intake of drugs such as NSAID'S, certain antibiotics, and anticonvulsants. It is characterized by rapidly rupturing vesicles leading to ill-defined erosions in the oral cavity and encrusted lip lesions. These lesions are usually difficult to differentiate from other vesiculo bullous and ulcerative lesions which would have a similar presentation and the absence of skin lesions can sometimes lead to misdiagnosis. Drug induced EM has an acute onset and is a self-limiting inflammatory hypersensitivity reaction that causes blistering and ulcerations of the skin and mucous membrane. The lesions heal following the discontinuation of the causative medications. This case report describes a case of drug induced erythema multiforme of the oral cavity that occurred consequent to the intake of Tab.Diclofenac Sodium and Tab.Cephelexin. The patient developed painful, bleeding, burning ulcerations with severe crustations on the upper, and lower lip, lateral and ventral surface of tongue, hard palate and retro molar regions. The case was managed with corticosteroids.

Cutaneous adverse drug reactions are undesirable cutaneous changes caused by medications. Drug eruptions can mimic a wide range of dermatoses that include exanthematous (morbilliform), urticarial, pustular, bullous, papulosquamous, or granulomatous lesions, and sometimes these eruptions may present with annular, polycyclic, or polymorphous configurations. The correct identification of a cutaneous drug eruption depends on a high index of suspicion, detailed medication exposure history, chronologic evaluation of the causal relationships between drug exposures and eruptions, and the exclusion of other infectious or idiopathic diseases. Most drug eruptions are annoying but self-limited, usually resolving after the withdrawal of the causative agents. Rarely, patients have severe cutaneous adverse reactions, such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and drug reaction with eosinophilia and systemic symptoms (DRESS), which are potentially lethal adverse drug reactions that involve the skin and mucous membranes and may also damage internal organs. Prompt recognition of the alarming signs of severe cutaneous adverse reactions and providing adequate treatment may thus be life-saving. We present the main clinical presentations, histopathology, possible implicated medications, and treatment of cutaneous adverse drug reactions that can present in annular configurations.

Our case highlights the occurrence of severe cutaneous adverse reactions with flurbiprofen use and alerts physicians to its odds with safer drugs.