New insights in toxic epidermal necrolysis (Lyell's syndrome): clinical considerations, pathobiology and targeted treatments revisited

Toxic Epidermal Necrolysis: A Clinical and Therapeutic Review

Toxic Epidermal Necrolysis is a rare dermatological condition with high mortality and serious consequences on its survivors. Despite having been first described in 1956, its pathophysiology remains uncertain, mainly regarding its mechanisms, although it seems that certain apoptosis pathways are pivotal in starting keratinocytes' apoptosis and in activating T cells, especially those mediated by tumour necrosis factor, Fas-FasL and granulysin. In general, its aetiology and presentation are consensual, being defined as a generalized necrolysis of the epidermis that occurs as an uncontrolled immune response to a specific drug or one of its metabolites, highlighting cotrimoxazole and allopurinol as the most important. This necrolysis leads to a massive shedding of the epidermal layer of the skin, with stronger incidences in the torso, upper limbs and face. Its complications tend to be severe, noting that septic ones are responsible for over half of the disease's mortality. Nearly all survivors develop long-term sequelae, namely hypertrophic scarring and skin pigmentation anomalies. Regarding treatment, many different opinions arise, including contradictory ones, regarding more importantly immunomodulation therapies that have been the focus of several studies through the years. It is safe to state that supportive therapy is the only modality that has significantly strong evidence backing its efficacy in reducing mortality and improving prognosis, which have improved in the past years as general health care quality increased. In conclusion, it is imperative to say that more research is needed for new potential therapies with large study populations and more scientific rigor. Likewise, investigation towards its basic pathophysiology should also be promoted, mainly at a biomolecular level, allowing for an improved prevention of this illness.

Case Report: Positive Outcome of a Suspected Drug-Associated (Immune Mediated) Reaction in a 4-Year-Old Male French Bulldog

Toxic epidermal necrolysis (TEN) is a rare and severe life-threatening syndrome characterized by apoptosis of keratinocytes resulting in devitalization of the epidermis affecting more than 30% of skin surface. In humans and animals, this condition is mostly triggered by drugs. Identification of the putative agent and its withdrawal are crucial to successful management of a patient with TEN. In this case study, we report the clinical features, histopathological findings and management of a dog with TEN. A 4-year-old intact male French bulldog presented with acute onset of severe lethargy and cutaneous ulcerations on the footpads, scrotum, and hind limbs associated with marked pain. A Stevens-Johnson syndrome/TEN was suspected and drugs, especially beta-lactams, were withdrawn. Histopathology confirmed the diagnosis of epidermal necrosis. Advanced supportive therapy, pain management and skin care led to rapid remission. Early identification and removal of the suspected medication was crucial to improving TEN prognosis in this dog. Antibiotics (penicillin, ampicillin, cephalexin, and sulfonamides) are frequently involved in adverse cutaneous reactions in dogs. Ideal treatment remains elusive is humans and dogs and this disease has a poor prognosis. Supportive care combined with pain management and treatment of the cutaneous ulcerations is essential.

Responsiveness to i.v. immunoglobulin therapy in patients with toxic epidermal necrolysis: A novel pharmaco-immunogenetic concept

Toxic epidermal necrolysis (TEN) represents a rare drug-induced autoimmune reaction with delayed-type hypersensitivity that initiates the process of developing massive keratinocyte apoptosis, dominantly in the dermoepidermal junction. Although the etiopathophysiology has not yet been fully elucidated, the binding of Fas ligand (FasL, CD95L) to the Fas receptor (CD95) was shown to play a key role in the induction of apoptosis in this syndrome. The knowledge of the role of immunoglobulin G (IgG) in inhibition of Fas-mediated apoptosis contributed to the introduction of i.v. Ig (IVIg) in the therapy of TEN patients. Despite great enthusiasm for this therapy at the end of the 1990s, subsequent studies in various populations and meta-analyses could not unequivocally confirm the efficacy of the IVIg-based treatment concept. Today, therefore, we are faced with the dilemmas of how to adjust therapy of TEN patients most effectively, which patients could benefit from IVIg therapy and what dose of the preparation should be administrated. The ground-breaking question is: do the host genetic profiles influence the responsiveness and side-effects of IVIg therapy in TEN patients? Based on recent pharmacological, immunological and genetic findings, we suggest that the variability of IVIg therapy outcomes in TEN patients may be related to functional variants in Fas, FasL and Fc-γ receptor genes. This novel concept could lead to improved quality of care for patients with TEN, facilitating personalized therapy to reduce mortality.

Attenuation of Wnt/β-catenin signaling in patients with 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. Current studies have suggested that the pathobiology of drug-mediated SJS/TEN involves a dysregulation of cellular immunity with overwhelming activation of cytotoxic T lymphocytes. The canonical Wnt signaling pathway plays important roles in T cell development and activation, which may provide potential avenues for alleviating dysregulated immunity in SJS/TEN. In this study, we aimed to assess the implication of Wnt signaling in drug-reactive T cells in SJS/TEN. We showed downregulation of Wnt signaling components, including T cell factor 1 (TCF-1)/lymphoid enhancer binding factor 1 (LEF-1) transcription factors, in SJS/TEN patients, suggesting that canonical Wnt signaling is regulated during cytotoxic T cell responses in SJS/TEN. Further analyses demonstrated that engagement of the T cell receptor by antigen encounter and treatment of a prognostic marker of SJS/TEN, IL-15, in vitro led to the downregulation of LEF-1 and TCF-1 expression in CD8+ T cells. Enhancement of Wnt signaling by adding the Wnt activators attenuated ex vivo activation of drug-specific T cells from SJS/TEN patients, indicating a functional involvement of Wnt signaling in the pathomechanism of SJS/TEN. These findings provide additional insight into the immunopathogenesis and therapeutic intervention of this devastating condition.

Pancytopenia in a Patient with Stevens-Johnson Syndrome: A Case Report with Literature Review

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare conditions triggered due to a medication that involves the necrosis and desquamation of the skin and mucous membranes. Only one out of 1,000,000 people are affected by the condition. The exact pathophysiology of the disease is still unknown. However, many complications of the disease can occur; pancytopenia and pleural effusion are an even rarer find. Here we present a case of a 17-year-old male who presented with fever and rash for 15 days associated with bleeding per rectum, hemoptysis, and conjunctival hemorrhages. Laboratory investigations showed severe pancytopenia, deranged liver function tests (LFTs), and hypocellular bone marrow. The patient started showing improvement after 10 days post-admission with supportive care and multiple transfusions.

An Interesting Case of Carbamazepine-Induced Stevens-Johnson Syndrome

A 29-year-old Black female patient was admitted to a psychiatric ward with symptoms of major depressive disorder with psychosis. The patient was started on amitriptyline 50 mg/day and haloperidol 10 mg/day. On day 4 post-admission, the preferred first-line antidepressant, fluoxetine, became available and the patient was switched from amitriptyline to fluoxetine 20 mg/day. On the same day, the dose of haloperidol was reduced to 5 mg/day. Thirteen days post-initiation of these medications the patient became talkative, associated with emotional lability, an expansive mood, irritability and restlessness. The working diagnosis was changed to bipolar affective disorder in the manic phase. Fluoxetine was discontinued and carbamazepine 600 mg/day was added to the patient's treatment regimen. Her manic symptoms started to resolve; however, 14 days post-initiation of carbamazepine, the patient had a fever; itchy, discharging eyes; respiratory distress; generalised symmetrical erythematosus rash; buccal ulceration; and conjunctival injection with difficulty opening her eyes. Carbamazepine was immediately discontinued and the patient received intravenous fluid resuscitation. The patient recovered considerably after 12 days of symptomatic and supportive management, and was transferred back to the psychiatric ward for the continuation of bipolar disorder management. Lithium therapy was instituted and the patient was subsequently discharged. Using the Algorithm of Drug causality for Epidermal Necrolysis (ALDEN) Stevens-Johnson Syndrome/toxic epidermal necrolysis (SJS/TEN) drug causality scoring system, carbamazepine and fluoxetine were evaluated as 'very probable' and 'possible' causes of SJS, respectively, in this patient. Fluoxetine-induced SJS was considered on account of previous case reports, however no evidence of causality was found in this patient. Consecutive administration with a potential increase in carbamazepine due to inhibition of cytochrome P450 (CYP) 3A4 metabolism by fluoxetine was also not ruled out. A diagnosis of carbamazepine-induced SJS was made and was considered an idiosyncratic adverse drug reaction.

Rapidly Progressing Severe Cutaneous Adverse Reaction With Acute Kidney Injury After Drug Exposure: An Uncommon Presentation

Toxic epidermal necrolysis syndrome (TEN) is a rare severe cutaneous adverse drug reaction that involves skin and mucous membranes. We describe a case of TEN presenting with stage III acute kidney injury, rhabdomyolysis, and acute respiratory failure likely triggered by allopurinol for recently diagnosed gout. Prompt diagnosis, multidisciplinary management, including aggressive resuscitation, cardiorespiratory support, intravenous immunoglobulin therapy, and daily wound care resulted in a positive outcome despite a predicted mortality greater than 60%. Although allopurinol is a known triggering agent, TEN presenting with rhabdomyolysis and acute kidney injury is rare.

Toxic epidermal necrolysis and concurrent granulomatosis with polyangiitis (Wegener's granulomatosis). Management of a rare case and review of the literature

Toxic epidermal necrolysis (TEN) is a rare, acute life-threatening mucocutaneous disorder that is characterised by epidermal loss/exfoliation exceeding 30% total body surface area (TBSA) and is on a spectrum that includes erythema multiforme and Stevens–Johnson syndrome (SJS). It is estimated that 80% of TEN cases are related to medication reactions; the association based on the recognition that TEN usually develops 1–3 weeks following administration of the suspect drug. It is agreed that primary treatment consists of prompt withdrawal of causative drugs and transfer to a regional burn unit. Transfer to a burn unit, no more than 7 days after onset of symptoms, has been acknowledged as reducing the risk of infections, hospital length of stay and infection-related mortality. Due to the uncertainty surrounding TEN pathogenesis, several different modalities have been proposed for the treatment of TEN, including high-dose intravenous immunoglobulins, plasmapheresis, cyclophosphamide, cyclosporine and systemic steroids; however, these therapies are relatively ineffective. The use of systemic corticosteroids for treatment of TEN has in particular been deemed controversial due to associations with increased infections leading to greater length of hospital stay and increased mortality.

Granulomatosis with polyangiitis (GPA), formerly known as Wegener’s granulomatosis, is a rare relapsing-remitting disorder of unknown aetiology, characterised by granulomatosis inflammation and necrotising vasculitis predominantly affecting small- to medium-sized vessels. While a 5-year survival rate of 75–83% is now realised, relapse and associated morbidity is of concern.

The established treatment for GPA follows the recommendations of the French National Authority for Health (HAS) for systematic necrotising vasculitis. With induction treatment, it is recommended that GPA be treated with a combination of systemic corticosteroids and immunosuppressants.

A review of the literature failed to identify any previous case where both of these conditions coincide. Our search was conducted through databases which included MEDLINE, PubMed, Scopus, AMED, CINAHL and EMBASE, using keywords: toxic epidermal necrolysis, Wegener’s granulomatosis, granulomatosis with polyangiitis. We submit the rare case of a 22-year-old woman who presented to our regional burn unit with both GPA and TEN, and we discuss the presentation, investigation and multidisciplinary management of the patient, as well as reviewing the literature regarding these two conditions.

Toxic epidermal necrolysis is a potentially fatal condition where there is a large area of skin exfoliated after the body’s reaction to a particular medication. Its treatment is largely by stopping the medication that is thought to have caused this reaction and also by regular dressings, thus keeping the area clean from any infection. Granulomatosis with polyangiitis, also known as Wegener’s granulomatosis, is another potentially fatal condition. Its treatment is very specific; however, this treatment may be harmful to a patient with toxic epidermal necrolysis. We describe the management of a patient who presented with both conditions, which is an extremely rare event. We describe the diagnosis and treatment during the patient’s inpatient stay at a regional burns unit. From this case report we have shown insight into the multidisciplinary management needed to manage such a complex patient, who made a full recovery.

Role of Oxidative and Nitrosative Stress in Pathophysiology of Toxic Epidermal Necrolysis and Stevens Johnson Syndrome-A Pilot Study

Background:

Oxidative and nitrosative stress caused by drug metabolism may be a trigger for keratinocyte apoptosis in the epidermis seen in toxic epidermal necrolysis (TEN) and Stevens Johnson syndrome (SJS).

Aims:

To estimate oxidative damage in the serum and to examine the role of nitric oxide in mediating epidermal damage in patients with TEN and SJS.

Materials and Methods:

A prospective study was conducted among TEN and SJS patients and controls in a tertiary care center between January 2006 and February 2010. Patients with a maculopapular drug rash without detachment of skin constituted the control group 1 (drug exposed). Patients without a drug rash constituted the control group 2 (drug unexposed). The serum values of protein carbonyls, malondialdehyde, conjugated diene and nitrates were measured. Two-group comparison with the non-parametric Mann–Whitney U test was used. Significance of differences if any was established using Pearson's Chi-square test.

Results:

Ten patients in the SJS-TEN group (study group), 8 patients in control group 1 and 7 patients in control group 2 were included. More than one drug was implicated in 4/10 patients in group 1 and 3/8 patients in group 2. SCORTEN of 0, 1 and 3 at admission were seen in 2, 6 and 2 patients, respectively. The serum values of protein carbonyls, malondialdehyde, conjugated diene and nitrates were not significantly increased in the study group when compared to the controls.

Conclusions:

There was no elevation of oxidative stress markers in patients with TEN and SJS as compared to the control population.

A 15-year review of pediatric toxic epidermal necrolysis

Owing to the rare, yet serious nature of toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS), the authors would like to describe our experience with 41 pediatric patients to contribute to the current clinical understanding of the disease. From records at a single institution, 41 patients ≤18 years of age with a diagnosis of SJS or TEN were retrospectively identified. Data were obtained from the hospital's medical record, and a variety of variables were collected, including causative agent, percentage of total body surface area (%TBSA) slough, ocular involvement, medical treatment, operative procedures, time to wound closure, ventilator days, intensive care unit length of stay, and associated hospital mortality. Of the pediatric TEN patients included, the mean epidermal sloughing was 39.7 ± 26% TBSA. The presumptive inciting agent was a medication in 90% of cases. Mycoplasma pneumoniae was implicated in two cases (5%). The average time between onset of symptoms and burn intensive care unit admission was 3.6 ± 2.0 days. Acutely, 73% of patients exhibited ocular involvement, 90% needed supplemental enteral nutritional support, and 51% required mechanical ventilation. On average, subjects spent 19.9 ± 13.9 days in the intensive care unit. While acute mortality was 0%, 100% of patients still experienced long-term complications and 30% required follow-up procedures. When compared to current literature, the outcomes of our patients were similar to that of pediatric TEN at other institutions. While acute mortality is typically better within the pediatric population, patients still experience a significant level of morbidity and have serious long-term sequelae.

Recent advances of pharmacogenomics in severe cutaneous adverse reactions: immune and nonimmune mechanisms

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS) are severe cutaneous adverse reactions (SCAR) which are majorly caused by drugs. Though the incidence rate is low, SCAR sometimes can be life-threatening and leads to lifelong sequelae. Many pharmacogenomic associations in immune and nonimmune related genes with the development of SCAR have been discovered recently and the pharmacogenetic tests have been applied to prevent specific drug-induced SCAR. In this review, we discuss the recent advances of pharmacogenomics in SCAR.

Erythema multiforme, Stevens-Johnson syndrome and toxic epidermal necrolysis: a comparative review

BACKGROUND

Human erythema multiforme (EM) and Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are separate conditions. There is no consensus on classification criteria for the eponymous diseases in animals.

RESULTS

Animal EM is very different from 90% of human EM, which is herpes virus associated (HAEM). Animals lack acrally distributed, typical raised targets. Unlike canine parvovirus 'EM', HAEM is not an active infection. Animal EM is often attributed to drugs, but this is rarely proved. Conversely, human and animal SJS/TEN are almost identical, life-threatening disorders of epidermal necrosis and detachment, typically triggered by drugs (occasionally by infectious agents). Both EM and SJS/TEN are mediated by cytotoxic lymphocyte responses against altered keratinocytes (infectious agents or drugs). Apoptosis results from direct cytotoxicity or through soluble mediators, namely Fas ligand, granzymes, perforin and granulysin. Diagnosis in humans is clinicopathological, with emphasis on clinical lesions; histopathology confirms the pathological process as interface (cytotoxic) dermatitis. Human EM is self-limiting; only recurrent and rare persistent cases require antiviral/immunosuppressive therapies. Drug-induced EM responds to drug withdrawal. Idiopathic canine EM (>40%) is usually chronic, refractory to treatment and may represent heterogeneous conditions. Early identification and removal of the causative drug and high-quality supportive care are critical in SJS/TEN. Mortality rate is nevertheless high.

CONCLUSIONS AND CLINICAL IMPORTANCE

(1) Histopathological lesions do not reliably differentiate EM, SJS and TEN. (2) A multicentre study to develop a consensus set of clinical criteria for EM and SJS/TEN in animals is overdue. (3) No adjunctive therapies, including intravenous immunoglobulin and ciclosporin, have met evidence-based standards.

Clinical and Microscopic Characteristics of Canine Toxic Epidermal Necrolysis

Canine toxic epidermal necrosis (TEN), a rare and life-threatening cutaneous drug reaction, traditionally has been described as full-thickness devitalization of the epidermis with minimal dermal inflammation; however, few reports detail the histologic findings. We characterize the clinical features and histologic variations of 3 canine TEN patients. Clinically, irregular erythematous and purpuric macules evolved into widespread and severely painful erosions. The number of eroded mucosae varied; however, periocular and perilabial mucocutaneous junctions frequently were affected. Thirteen of 17 biopsies were evaluated. Apoptosis at multiple epidermal levels was the most common pattern of epidermal necrosis (12/13 biopsies, 92%). In contrast, full-thickness coagulation necrosis was present less often (7/13 biopsies, 52%). Lymphocytic interface dermatitis was the predominant inflammatory pattern, and intraepidermal lymphocytes, along with fewer histiocytes, were present to some degree in all samples along with lymphocytic satellitosis of apoptotic keratinocytes. The sequence of changes points to lymphocyte-mediated keratinocyte apoptosis as an early step in lesion development with subsequent variation in progression to coagulation necrosis among patients. Histopathologic changes overlapped with those reported for erythema multiforme, in contrast to traditional histologic descriptions of canine TEN. A specific algorithm for assessment of drug causality in epidermal necrolysis (ALDEN) was applied for each patient; carprofen was associated with a probable score for causality in 1 dog. Clinicians should be encouraged to take multiple biopsies in TEN suspect cases as nearly 25% of all biopsies lacked epithelium and were not diagnostic.

Effect of N-acetylcysteine combined with infliximab on toxic epidermal necrolysis. A proof-of-concept study

INTRODUCTION

The pathophysiology of toxic epidermal necrolysis (TEN) is thought to be related to a drug-induced oxidative stress combined with TNFα overexpression by keratinocytes. None of the current treatments for TEN including systemic corticosteroids, cyclosporine and intravenous administration of immunoglobulins has proven superior over supportive care only.

METHODS

A total of 10 TEN patients were enrolled to be treated at admission in burn units with the antioxidant N-acetylcysteine [NAC, 150mg/kg in a 20-h intravenous (IV) administration], or the combination of the same IV NAC perfusion with the anti-TNFα antibody infliximab (Remicade(®)), administered at a 5mg/kg dosage as a single 2-h IV administration. TEN was confirmed by a skin biopsy taken from a bullous lesion. At entry in the trial and 48h later, the illness auxiliary score (IAS) of clinical severity was determined and the extent in altered skin area (erythema and blisters) was assessed as a relative body area. Skin biopsies of both clinically uninvolved and erythematous areas were collected and immunohistochemistry was performed for assessing the density of inflammatory cells (CD8+ T cells, CD68+ macrophages) and keratinocytes enriched in intracellular calcium (Ca(++)) identified by the Mac387 anti-calprotectin antibody.

RESULTS

No unexpected drug-induced adverse event was noticed. After 48h of both treatment modalities, improvements were not observed in the extent of skin involvement and in IAS. Immunohistopathology showed the absence of reduction in the amount of intraepidermal inflammatory cells. An increased intracellular Ca(++) load in clinically uninvolved keratinocytes and in erythematous epidermis was noticed. This latter finding suggested the progression in the way of the apoptotic process. On burn unit discharge, the survival in each modality of treatment was not improved compared to the expected outcomes determined from the IAS at admission.

CONCLUSIONS

In this proof-to-concept attempt, NAC treatment or its combination with infliximab did not appear to reverse the evolving TEN process.

Multi-indication carbamazepine and the risk of severe cutaneous adverse drug reactions in Korean elderly patients: a Korean health insurance data-based study

Objective

To evaluate the risk of severe cutaneous adverse drug reactions (SCAR) after exposure to multi-indication antiepileptic drugs for in Korean elderly patients.

Methods

We used a nationwide database from the Korean Health Insurance Review and Assessment Service claims constructed for the monitoring of drug utilization among the entire Korean elderly population from January 2005 to June 2006. We identified cases of SCARs among inpatients aged ≥65 years and those newly diagnosed with erythema multiforme according to the International Classification of Diseases, 10th revision code (L51). Each case was matched to four controls for gender, age, and the first hospitalization date as the index date. The use of carbamazepine, gabapentin, lamotrigine, topiramate, phenobarbital, phenytoin, and valproate during a 60-day period before the index date was compared. A conditional logistic regression analysis was performed to calculate the odds ratios (OR) and 95% confidence intervals (CI) of SCARs for antiepileptic drug.

Results

We identified 286 cases of SCAR and 1,144 matched controls. Among the 25 patients who were prescribed antiepileptic drugs within 60 days of the index date. There were 11 cases (3.8%) of severe ocular manifestations, and most elderly patients were first-time or short-term users of antiepileptic drugs. Among the 10 cases of carbamazepine use, only 2 cases were prescribed carbamazepine for seizure. All antiepileptic drugs were associated with an increased SCAR risk (adjusted OR = 3.42, 95% CI: 1.75–6.63). The SCAR risk was highest in patients treated with carbamazepine (adjusted OR = 10.39, 95% CI: 2.64–40.86, for multi-indication; adjusted OR = 6.84, 95% CI: 1.55–30.10, for neuropathic pain).

Conclusion

Carbamazepine use was associated with a nearly 10-fold increase in severe cutaneous drug reactions in Korean elderly patients. This association was consistently high with SCAR patients who received carbamazepine for neuropathic pain.

Cutaneous drug reactions in children: an update

Cutaneous drug reactions account for a large proportion of adverse drug reactions. Cutaneous drug reactions can be very challenging to diagnose. They can mimic many other skin diseases; this is especially evident during childhood, when viral exanthems are commonplace. Also, if a patient is taking numerous medications, establishing causality to a specific drug can be multifaceted and difficult. The purpose of this review is to highlight an approach to the diagnosis of a suspected cutaneous drug reaction in a child. We have classified different types of drug eruptions by morphology: exanthematous, urticarial, pustular, and bullous. Within each of these groups we have divided them into simple, benign, or non-febrile and complex or febrile reactions. We also include a miscellaneous group to ensure a methodical review.

Toxic Epidermal Necrolysis and Graft-versus-Host Reaction: Revisiting a Puzzling Similarity

Drug-induced toxic epidermal necrolysis (TEN) and acute cutaneous graft-versus-host reaction (GVHR) under immunopreventive therapy share some histopathological resemblance. So far, there are no serum biomarkers and no immunohistochemical criteria distinguishing with confidence and specificity the skin lesions of TEN and GVHR. Both diseases present as an inflammatory cell-poor necrotic reaction of the epidermis. This report compares three sets of 15 immunostaining patterns found in TEN, GVHR, and partial thickness thermal burns (PTTB), respectively. Three series of 17 skin biopsies were scrutinized. Irrespective of the distinct causal pathobiology of TEN and GVHR, similar secondary effector cells were recruited in lesional skin. Burns were less enriched in cells of the monocyte-macrophage disease. These cells likely exert deleterious effects in TEN and GVHR and cannot be simply regarded as passive bystanders. These life-threatening conditions are probably nursed, at least in part, by macrophages.

Idiosyncratic adverse drug reactions: current concepts

Idiosyncratic drug reactions are a significant cause of morbidity and mortality for patients; they also markedly increase the uncertainty of drug development. The major targets are skin, liver, and bone marrow. Clinical characteristics suggest that IDRs are immune mediated, and there is substantive evidence that most, but not all, IDRs are caused by chemically reactive species. However, rigorous mechanistic studies are very difficult to perform, especially in the absence of valid animal models. Models to explain how drugs or reactive metabolites interact with the MHC/T-cell receptor complex include the hapten and P-I models, and most recently it was found that abacavir can interact reversibly with MHC to alter the endogenous peptides that are presented to T cells. The discovery of HLA molecules as important risk factors for some IDRs has also significantly contributed to our understanding of these adverse reactions, but it is not yet clear what fraction of IDRs have a strong HLA dependence. In addition, with the exception of abacavir, most patients who have the HLA that confers a higher IDR risk with a specific drug will not have an IDR when treated with that drug. Interindividual differences in T-cell receptors and other factors also presumably play a role in determining which patients will have an IDR. The immune response represents a delicate balance, and immune tolerance may be the dominant response to a drug that can cause IDRs.

Toxic epidermal necrolysis related to Cisplatin and pemetrexed for metastatic non-small cell lung cancer

BACKGROUND

Toxic epidermal necrolysis (TEN) is an uncommon but life-threatening adverse drug reaction. Pemetrexed is a multitargeted antifolate. It was first used in combination with cisplatin as a front-line treatment for malignant pleural mesothelioma. The same combination is nowadays approved in the first-line setting for locally advanced or metastatic nonsquamous non-small cell lung cancer (NSCLC).

PATIENT AND METHODS

We report the case of a 50-year-old man treated for metastatic NSCLC. Within 5 days after administration of the second cycle of cisplatin and pemetrexed, he developed large blisters, which secondarily became hemorrhagic, and mucosal lesions. The characteristic clinical appearance, the histopathological findings, and the clinical course were decisive for the diagnosis of TEN. Treatment with systemic steroids and intravenous antibiotics as well as topical wound treatment led to resolution and improvement of his general condition.

CONCLUSIONS

To the best of our knowledge, this is the third case of TEN due to pemetrexed in a patient with NSCLC. Clinicians should be aware of TEN as a rare but potentially fatal disorder requiring hospitalization and multidisciplinary management.

Rhabdomyolysis as a potential complication of carbamazepine-induced toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) is a rare and severe exfoliative skin disorder characterized as widespread epidermis destruction and is usually a drug-induced condition. TEN has a high mortality rate, and multisystemic involvement is very frequent. Gastrointestinal, respiratory, hepatic, pancreatic, ocular, and hematological disturbances are common complications of TEN. Here, we report on a 30-year-old male with TEN who developed concurrent rhabdomyolysis. The exact relationship between TEN and rhabdomyolysis remains unknown. Because of lack of underlying etiology, we hypothesized that rhabdomyolysis is a potential TEN-related complication.

A fatal case of cutaneous adverse drug-induced toxic epidermal necrolysis associated with severe rhabdomyolysis

Toxic epidermal necrolysis represents an immunologic reaction to a foreign antigen and is most often caused by drugs. Atorvastatin, a blood cholesterol-lowering agent, is a recognized cause of rhabdomyolysis; while naproxen, a widely used nonsteroidal anti-inflammatory drug, is a known cause of photo-induced skin lesions. We report the first fatal case of drug-induced toxic epidermal necrolysis associated with severe muscle necrosis due to the use of a nonsteroidal anti-inflammatory drug and a statin with very high levels of creatine phosphokinase leading to acute kidney injury, disseminated intravascular coagulation, and complete skin necrosis leading to death.

Recent advances in the genetics and immunology of Stevens-Johnson syndrome and toxic epidermal necrosis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN) are rare but life-threatening severe cutaneous adverse reactions (SCARs), which are majorly (65-75%) induced by a variety of drugs. SJS/TEN could be recognized as SCARs or drug immune reactions, if the reactions are elicited by drugs. The recent studies suggested that SJS/TEN is a specific immune reaction initiated by the cytotoxic T lymphocytes (CTLs) via human leukocyte antigens (HLAs)-restricted pathway. The patho-mechanism involving HLA-restricted presentation of a drug or its metabolites for T-cell activation is supported by the findings of strong genetic associations with HLA alleles (e.g. HLA-B*15:02 and carbamazepine-SJS/TEN, and HLA-B*58:01 and allopurinol-SJS/TEN). However, the genetic associations of SJS/TEN or drug induced cutaneous immune reactions are complex, which are drug specific and ethnicity specific. The genetic polymorphisms and diversity of HLA alleles may provide different binding affinities for drug antigens to launch the activation of specific CTLs responses, further leading to the unique clinical manifestations in SJS/TEN. Fas-FasL and perforin/granzyme B have been advocated mediating the epidermal necrosis in SJS/TEN. Our recent study showed that granulysin, a cytotoxic protein produced by CTLs or natural killer (NK) cells, is the key mediator for disseminated keratinocyte death in SJS/TEN. From the point of view of a physician, the profounder understanding of the genetic predisposition and patho-mechanism we discover, the better strategies for prevention, clinical management, and therapeutic methods of SJS/TEN we can develop in the near future.

Dual face apoptotic machinery: from initiator of apoptosis to guardian of necroptosis

In this issue of Immunity, Bonnet et al. (2011) show that skin-specific ablation of the adaptor protein FADD sensitizes keratinocytes to RIPK3-dependent necrotic cell death, which leads to severe skin inflammation.

Revisiting cutaneous adverse reactions to pemetrexed

Pemetrexed (Alimta®) is a multitargeted antifolate drug approved as a single agent or in combination with cisplatin for the treatment of a small number of malignancies including advanced and metastatic non-squamous non-small cell lung cancer (NSCLC), and malignant pleural mesothelioma. This review reports the recent peer-reviewed publications and original findings regarding cutaneous adverse reactions (CARs) to pemetrexed. Pemetrexed-related CARs are frequently reported under the unspecific term 'skin rash'. However, more specific diseases were tentatively identified as alopecias, urticarial vasculitis, acute generalized exanthematous pustulosis, toxic epidermal necrolysis, radiation recall dermatitis and pityriasis lichenoides. Most of the skin reactions occur shortly after pemetrexed administration. As with methotrexate-related CARs, the cell cycle arrest in the S phase may be regarded as a direct and major cause of the cytotoxic pathobiology. An adverse immune reaction is unlikely. In conclusion, pemetrexed is responsible for CARs exhibiting a variety of clinical presentations. Their origin is likely attributed to direct cytotoxicity following the cell cycle arrest in the S phase and cell necrosis.

Facing up to toxic epidermal necrolysis

Toxic epidermal necrolysis (TEN) is a rare but life-threatening mucocutaneous adverse drug reaction. The disease is characterized by a specific and extensive destruction of the epidermis and mucosal epithelia, particularly of the mouth, genitalia and eyes. The TEN pathomechanism is probably initiated by a toxic drug metabolism inside keratinocytes, leading to a self-activation of apoptosis and necrosis. These events are boosted by additional effects of T lymphocytes and macrophages. At present there is still a lack of validated mainstay treatment for TEN. However, a few treatment modalities have been reported to halt TEN progression in some patients.

Stevens-Johnson syndrome and toxic epidermal necrolysis: what do we know?

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are rare but severe cutaneous adverse reactions related to a variety of medications. Although rare, SJS and TEN have a significant impact on public health because of high mortality. Also, if the SJS/TEN physiopathology is still unclear, a specific immune response to one or more drugs is involved, constituting a form of delayed-type hypersensitivity. Patients with SJS/TEN are often critically ill; therefore, they must be admitted to hospitals capable of delivering critical care. Currently, no treatment modality has been established as standard for these patients; therefore, therapy is primarily supportive and symptomatic and involves a multidisciplinary approach.