Esophageal stricture secondary to drug-induced toxic epidermal necrolysis

Severe Delayed Cutaneous and Systemic Reactions to Drugs: A Global Perspective on the Science and Art of Current Practice

Most immune-mediated adverse drug reactions (IM-ADRs) involve the skin, and many have additional systemic features. Severe cutaneous adverse drug reactions (SCARs) are an uncommon, potentially life-threatening, and challenging subgroup of IM-ADRs with diverse clinical phenotypes, mechanisms, and offending drugs. T-cell-mediated immunopathology is central to these severe delayed reactions, but effector cells and cytokines differ by clinical phenotype. Strong HLA-gene associations have been elucidated for specific drug-SCAR IM-ADRs such as Stevens-Johnson syndrome/toxic epidermal necrolysis, although the mechanisms by which carriage of a specific HLA allele is necessary but not sufficient for the development of many IM-ADRs is still being defined. SCAR management is complicated by substantial short- and long-term morbidity/mortality and the potential need to treat ongoing comorbid disease with related medications. Multidisciplinary specialist teams at experienced units should care for patients. In the setting of SCAR, patient outcomes as well as preventive, diagnostic, treatment, and management approaches are often not generalizable, but rather context specific, driven by population HLA-genetics, the pharmacology and genetic risk factors of the implicated drug, severity of underlying comorbid disease necessitating ongoing treatments, and cost considerations. In this review, we update the basic and clinical science of SCAR diagnosis and management.

Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis--A Comprehensive Review and Guide to Therapy. I. Systemic Disease

The intent of this review is to comprehensively appraise the state of the art with regard to Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with particular attention to the ocular surface complications and their management. SJS and TEN represent two ends of a spectrum of immune-mediated, dermatobullous disease, characterized in the acute phase by a febrile illness followed by skin and mucous membrane necrosis and detachment. The widespread keratinocyte death seen in SJS/TEN is rapid and irreversible, and even with early and aggressive intervention, morbidity is severe and mortality not uncommon. We have divided this review into two parts. Part I summarizes the epidemiology and immunopathogenesis of SJS/TEN and discusses systemic therapy and its possible benefits. We hope this review will help the ophthalmologist better understand the mechanisms of disease in SJS/TEN and enhance their care of patients with this complex and often debilitating disease. Part II (April 2016 issue) will focus on ophthalmic manifestations.

Clinical application of pharmacogenomics: the example of HLA-based drug-induced toxicity

Pharmacogenomics is gradually becoming more and more indispensable in modern medicine. In several cases, a pharmacogenomics test may alleviate serious drug-induced adverse reactions, if it precedes drug prescription. In this article, we provide an overview of the well-established HLA-based carbamazepine- and allopurinol-induced adverse reactions, as one of the most characteristic examples of the clinical application of pharmacogenomics, highlighting its regional impact in Southeast Asian populations in preventing adverse reactions of certain drug/allele pairs. This example provides useful insights towards evidence generation for policy implementation, including economic evaluation analysis, the implementation of pharmacogenomics testing procedures and monitoring of policy effectiveness, hence serving, per se or in the context of international collaborative efforts, as a model for similar cases in several national healthcare systems worldwide.

Toxic epidermal necrolysis and Stevens-Johnson syndrome

Toxic epidermal necrolysis (TEN) and Stevens Johnson Syndrome (SJS) are severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes. Both are rare, with TEN and SJS affecting approximately 1or 2/1,000,000 annually, and are considered medical emergencies as they are potentially fatal. They are characterized by mucocutaneous tenderness and typically hemorrhagic erosions, erythema and more or less severe epidermal detachment presenting as blisters and areas of denuded skin. Currently, TEN and SJS are considered to be two ends of a spectrum of severe epidermolytic adverse cutaneous drug reactions, differing only by their extent of skin detachment. Drugs are assumed or identified as the main cause of SJS/TEN in most cases, but Mycoplasma pneumoniae and Herpes simplex virus infections are well documented causes alongside rare cases in which the aetiology remains unknown. Several drugs are at "high" risk of inducing TEN/SJS including: Allopurinol, Trimethoprim-sulfamethoxazole and other sulfonamide-antibiotics, aminopenicillins, cephalosporins, quinolones, carbamazepine, phenytoin, phenobarbital and NSAID's of the oxicam-type. Genetic susceptibility to SJS and TEN is likely as exemplified by the strong association observed in Han Chinese between a genetic marker, the human leukocyte antigen HLA-B*1502, and SJS induced by carbamazepine. Diagnosis relies mainly on clinical signs together with the histological analysis of a skin biopsy showing typical full-thickness epidermal necrolysis due to extensive keratinocyte apoptosis. Differential diagnosis includes linear IgA dermatosis and paraneoplastic pemphigus, pemphigus vulgaris and bullous pemphigoid, acute generalized exanthematous pustulosis (AGEP), disseminated fixed bullous drug eruption and staphyloccocal scalded skin syndrome (SSSS). Due to the high risk of mortality, management of patients with SJS/TEN requires rapid diagnosis, evaluation of the prognosis using SCORTEN, identification and interruption of the culprit drug, specialized supportive care ideally in an intensive care unit, and consideration of immunomodulating agents such as high-dose intravenous immunoglobulin therapy. SJS and TEN are severe and life-threatening. The average reported mortality rate of SJS is 1-5%, and of TEN is 25-35%; it can be even higher in elderly patients and those with a large surface area of epidermal detachment. More than 50% of patients surviving TEN suffer from long-term sequelae of the disease.

Stevens-Johnson syndrome and toxic epidermal necrolysis: a review of the literature

OBJECTIVE

To perform a comprehensive review of Stevens-Johnson syndrome and toxic epidermal necrolysis.

DATA SOURCES

A MEDLINE search was performed for the years 1975 to 2003 using the keywords Stevens-Johnson syndrome and toxic epidermal necrolysis to identify relevant articles published in English in peer-reviewed journals.

STUDY SELECTION

All clinical studies that reported on 4 or more patients, review articles, and experimental studies that concerned disease mechanisms were selected and further analyzed. Clinical reports that included fewer than 4 patients were selected only if they were believed to carry a significant message about disease mechanism or therapy.

RESULTS

Stevens-Johnson syndrome and toxic epidermal necrolysis seem to be variants of the same disease with differing severities. A widely accepted consensus regarding diagnostic criteria and therapy does not exist at present. Despite the recent experimental studies, the pathogenic mechanisms of these diseases remain unknown. Although progress in survival through early hospitalization in specialized burn units has been made, the prevalence of life-long disability from the ocular morbidity of Stevens-Johnson syndrome and toxic epidermal necrolysis has remained unchanged for the past 35 years. Further progress depends on modification of the acute phase of the disease rather than continuation of supportive care. The available published evidence indicates that a principal problem in the pathogenesis is immunologic and that immunomodulatory intervention with short-term, high-dose intravenous steroids or intravenous immunoglobulin holds the most promise for effective change in survival and long-term morbidity.

CONCLUSIONS

The results of this review call for a widely accepted consensus on diagnostic criteria for Stevens-Johnson and toxic epidermal necrolysis and multicenter collaboration in experimental studies and clinical trials that investigate disease mechanisms and novel therapeutic interventions, respectively.

Ileal involvement in toxic epidermal necrolysis (Lyell syndrome)

Intestinal involvement in toxic epidermal necrolysis (TEN) has been identified only rarely. This report describes a case of TEN with ileal manifestations characterized by a profuse diarrhea with malabsorption, protein-losing enteropathy, and radiologically by multiple stenosis. After healing of the cutaneous lesions, total parenteral nutrition was initiated, resulting in a decreased diarrhea. However, after one month of total parenteral nutrition, malabsorption and protein-losing enteropathy continued and the radiological lesions were still present with an aspect consistent with a sclerotic process. A surgical resection of the pathological ileal segment was performed with end-to-end anastomosis. Pathological examination of the resected segment showed a necrosis of the ileal mucosa with a pattern similar to that of the epidermal necrosis. No sclerosis was observed. It seems that a prolonged total parenteral nutrition could have induced a complete healing of intestinal lesions. This case report is the first clinical, radiological, and histological study of an ileal involvement in TEN.

Toxic epidermal necrolysis (Lyell syndrome)

Toxic epidermal necrolysis is perhaps the most formidable disease encountered by dermatologists. Uncommon but not rare, toxic epidermal necrolysis occurs in 60 to 70 persons per year in France. It remains as puzzling a disorder as it was 34 years ago, when described by Lyell. Whether or not toxic epidermal necrolysis is the most severe form of erythema multiforme is still the subject of discussion. The physiopathologic events that lead to this rapidly extensive necrosis of the epidermis are not understood. Indirect evidence suggests a hypersensitivity reaction, but the search for potential immunologic mechanisms has resulted in little data to support this hypothesis. Accumulated clinical evidence points to drugs as the most important, if not the only, cause of toxic epidermal necrolysis. Sulfonamides, especially long-acting forms, anticonvulsants, nonsteroidal anti-inflammatory agents, and certain antibiotics are associated with most cases of toxic epidermal necrolysis. Many other drugs have been implicated in isolated case reports. All organs may be involved either by the same process of destruction of the epithelium as observed in the epidermis or by the same systemic consequences of "acute skin failure" as seen in patients with widespread burns. Sepsis is the most important complication and cause of death. Approximately 20% to 30% of all patients with toxic epidermal necrolysis die. Elderly patients and patients with extensive lesions have a higher mortality rate. Surviving patients completely heal in 3 to 4 weeks, but up to 50% will have residual, potentially disabling ocular lesions. The prognosis is improved by adequate therapy, as provided in burn units, that is, aggressive fluid replacement, nutritional support, and a coherent antibacterial policy. Corticosteroids, advocated by some in high doses to halt the "hypersensitivity" process, have been shown in several studies to be detrimental and should be avoided.

Dermatologic Problems in the Intensive Care Unit: Part I

Skin disorders are present in many patients hospitalized in the intensive care unit. They range in severity from being the reason for admission to being a nuisance acquired during care These cutaneous problems have been categorized into four groups: (1) serious skin diseases that may incur life-threatening complications; (2) subtle skin findings associated with systemic disorders that may be characterized by critical events; (3) prominent cutaneous manifestations that accompany life-threatening systemic diseases: and (4) skin disorders that develop as complications during intensive care. Diseases in the first category are discussed in this article. Diseases in the second category will be discussed in Part II. The remaining disorders will be covered in Parts III and IV.