Toxic epidermal necrolysis associated with severe hypocalcaemia, and treated with cyclosporin

Systemic interventions for treatment of Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and SJS/TEN overlap syndrome

BACKGROUND

Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and SJS/TEN overlap syndrome are rare, severe cutaneous adverse reactions usually triggered by medications. In addition to tertiary-level supportive care, various systemic therapies have been used including glucocorticoids, intravenous immunoglobulins (IVIGs), cyclosporin, N-acetylcysteine, thalidomide, infliximab, etanercept, and plasmapheresis. There is an unmet need to understand the efficacy of these interventions.

OBJECTIVES

To assess the effects of systemic therapies (medicines delivered orally, intramuscularly, or intravenously) for the treatment of SJS, TEN, and SJS/TEN overlap syndrome.

SEARCH METHODS

We searched the following databases up to March 2021: the Cochrane Skin Specialised Register, CENTRAL, MEDLINE, and Embase. We also searched five clinical trial registers, the reference lists of all included studies and of key review articles, and a number of drug manufacturer websites. We searched for errata or retractions of included studies.

SELECTION CRITERIA

We included only randomised controlled trials (RCTs) and prospective observational comparative studies of participants of any age with a clinical diagnosis of SJS, TEN, or SJS/TEN overlap syndrome. We included all systemic therapies studied to date and permitted comparisons between each therapy, as well as between therapy and placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as specified by Cochrane. Our primary outcomes were SJS/TEN-specific mortality and adverse effects leading to discontinuation of SJS/TEN therapy. Secondary outcomes included time to complete re-epithelialisation, intensive care unit length of stay, total hospital length of stay, illness sequelae, and other adverse effects attributed to systemic therapy. We rated the certainty of the evidence for each outcome using GRADE.

MAIN RESULTS

We included nine studies with a total of 308 participants (131 males and 155 females) from seven countries. We included two studies in the quantitative meta-analysis. We included three RCTs and six prospective, controlled observational studies. Sample sizes ranged from 10 to 91. Most studies did not report study duration or time to follow-up. Two studies reported a mean SCORe of Toxic Epidermal Necrosis (SCORTEN) of 3 and 1.9. Seven studies did not report SCORTEN, although four of these studies reported average or ranges of body surface area (BSA) (means ranging from 44% to 51%). Two studies were set in burns units, two in dermatology wards, one in an intensive care unit, one in a paediatric ward, and three in unspecified inpatient units. Seven studies reported a mean age, which ranged from 29 to 56 years. Two studies included paediatric participants (23 children). We assessed the results from one of three RCTs as low risk of bias in all domains, one as high, and one as some concerns. We judged the results from all six prospective observational comparative studies to be at a high risk of bias. We downgraded the certainty of the evidence because of serious risk of bias concerns and for imprecision due to small numbers of participants. The interventions assessed included systemic corticosteroids, tumour necrosis factor-alpha (TNF-alpha) inhibitors, cyclosporin, thalidomide, N-acetylcysteine, IVIG, and supportive care. No data were available for the main comparisons of interest as specified in the review protocol: etanercept versus cyclosporin, etanercept versus IVIG, IVIG versus supportive care, IVIG versus cyclosporin, and cyclosporin versus corticosteroids. Corticosteroids versus no corticosteroids It is uncertain if there is any difference between corticosteroids (methylprednisolone 4 mg/kg/day for two more days after fever had subsided and no new lesions had developed) and no corticosteroids on disease-specific mortality (risk ratio (RR) 2.55, 95% confidence interval (CI) 0.72 to 9.03; 2 studies; 56 participants; very low-certainty evidence). Time to complete re-epithelialisation, length of hospital stay, and adverse effects leading to discontinuation of therapy were not reported. IVIG versus no IVIG It is uncertain if there is any difference between IVIG (0.2 to 0.5 g/kg cumulative dose over three days) and no IVIG in risk of disease-specific mortality (RR 0.33, 95% CI 0.04 to 2.91); time to complete re-epithelialisation (mean difference (MD) -2.93 days, 95% CI -4.4 to -1.46); or length of hospital stay (MD -2.00 days, 95% CI -5.81 to 1.81). All results in this comparison were based on one study with 36 participants, and very low-certainty evidence. Adverse effects leading to discontinuation of therapy were not reported. Etanercept (TNF-alpha inhibitor) versus corticosteroids Etanercept (25 mg (50 mg if weight > 65 kg) twice weekly "until skin lesions healed") may reduce disease-specific mortality compared to corticosteroids (intravenous prednisolone 1 to 1.5 mg/kg/day "until skin lesions healed") (RR 0.51, 95% CI 0.16 to 1.63; 1 study; 91 participants; low-certainty evidence); however, the CIs were consistent with possible benefit and possible harm. Serious adverse events, such as sepsis and respiratory failure, were reported in 5 of 48 participants with etanercept and 9 of 43 participants with corticosteroids, but it was not clear if they led to discontinuation of therapy. Time to complete re-epithelialisation and length of hospital stay were not reported. Cyclosporin versus IVIG  It is uncertain if there is any difference between cyclosporin (3 mg/kg/day or intravenous 1 mg/kg/day until complete re-epithelialisation, then tapered off (10 mg/day reduction every 48 hours)) and IVIG (continuous infusion 0.75 g/kg/day for 4 days (total dose 3 g/kg) in participants with normal renal function) in risk of disease-specific mortality (RR 0.13, 95% CI 0.02 to 0.98, 1 study; 22 participants; very low-certainty evidence). Time to complete re-epithelialisation, length of hospital stay, and adverse effects leading to discontinuation of therapy were not reported. No studies measured intensive care unit length of stay.

AUTHORS' CONCLUSIONS

When compared to corticosteroids, etanercept may result in mortality reduction. For the following comparisons, the certainty of the evidence for disease-specific mortality is very low: corticosteroids versus no corticosteroids,  IVIG versus no IVIG and cyclosporin versus IVIG. There is a need for more multicentric studies, focused on the most important clinical comparisons, to provide reliable answers about the best treatments for SJS/TEN.

Successful Use of Cyclosporin A for Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis in Three Children

BACKGROUND/OBJECTIVES

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are medical emergencies. Mainstays of treatment include removal of the offending agent, supportive care, and wound care. The use of immunosuppressive agents such as corticosteroids and intravenous immunoglobulin (IVIg) is controversial. Some case reports and small studies report the successful use of cyclosporin A (CsA) for SJS/TEN in halting disease progression, fostering reepithelialization, and reducing mortality.

OBJECTIVE

To report on the efficacy of cyclosporine A in the treatment of SJS/TEN in three pediatric patients.

METHODS

We describe three pediatric patients seen at a tertiary care hospital in Boston, Massachusetts, diagnosed with SJS/TEN confirmed by skin biopsy who were successfully treated with CsA with improvements seen in time to cessation of disease progression or new lesion formation, reepithelialization, and duration of hospital stay.

RESULTS

The average time cessation of disease progression or new lesion formation after CsA administration was 2.2 days (range 1.5-3 days) and average time to remission or reepithelialization was 13 days (range 10-15 days). The average length of hospital stay was 11.7 days (range 4-19 days).

CONCLUSIONS

We describe three pediatric patients treated successfully with CsA and provide evidence for the use of cyclosporine in children with SJS/TEN. These results further support previous observations that CsA use for SJS/TEN produces consistently favorable outcomes. The results in this case series are limited by their observational nature. Additional trials are needed to evaluate the safety and efficacy of CsA use in children.

Cytotoxic proteins and therapeutic targets in severe cutaneous adverse reactions

Severe cutaneous adverse reactions (SCARs), such as Stevens-Johnson syndrome (SJS) and toxic epidermal necrosis (TEN), are rare but life-threatening conditions induced mainly by a variety of drugs. Until now, an effective treatment for SJS/TEN still remains unavailable. Current studies have suggested that the pathobiology of drug-mediated SJS and TEN involves major histocompatibility class (MHC) I-restricted activation of cytotoxic T lymphocytes (CTLs) response. This CTLs response requires several cytotoxic signals or mediators, including granulysin, perforin/granzyme B, and Fas/Fas ligand, to trigger extensive keratinocyte death. In this article, we will discuss the cytotoxic mechanisms of severe cutaneous adverse reactions and their potential applications on therapeutics for this disease.

Toxic epidermal necrolysis and Stevens-Johnson syndrome: a review

OBJECTIVES

The aims of this review are to summarize the definitions, causes, and clinical course as well as the current understanding of the genetic background, mechanism of disease, and therapy of toxic epidermal necrolysis and Stevens-Johnson syndrome.

DATA SOURCES

PubMed was searched using the terms toxic epidermal necrolysis, Stevens-Johnson syndrome, drug toxicity, drug interaction, and skin diseases.

DATA SYNTHESIS

Toxic epidermal necrolysis and Stevens-Johnson syndrome are acute inflammatory skin reactions. The onset is usually triggered by infections of the upper respiratory tract or by preceding medication, among which nonsteroidal anti-inflammatory agents, antibiotics, and anticonvulsants are the most common triggers. Initially the diseases present with unspecific symptoms, followed by more or less extensive blistering and shedding of the skin. Complete death of the epidermis leads to sloughing similar to that seen in large burns. Toxic epidermal necrolysis is the most severe form of drug-induced skin reaction and includes denudation of >30% of total body surface area. Stevens-Johnson syndrome affects <10%, whereas involvement of 10%-30% of body surface area is called Stevens-Johnson syndrome/toxic epidermal necrolysis overlap. Besides the skin, mucous membranes such as oral, genital, anal, nasal, and conjunctival mucosa are frequently involved in toxic epidermal necrolysis and Stevens-Johnson syndrome. Toxic epidermal necrolysis is associated with a significant mortality of 30%-50% and long-term sequelae. Treatment includes early admission to a burn unit, where treatment with precise fluid, electrolyte, protein, and energy supplementation, moderate mechanical ventilation, and expert wound care can be provided. Specific treatment with immunosuppressive drugs or immunoglobulins did not show an improved outcome in most studies and remains controversial. The mechanism of disease is not completely understood, but immunologic mechanisms, cytotoxic reactions, and delayed hypersensitivity seem to be involved.

CONCLUSION

Profound knowledge of exfoliative skin diseases is needed to improve therapy and outcome of these life-threatening illnesses.

Open trial of ciclosporin treatment for Stevens-Johnson syndrome and toxic epidermal necrolysis

Background Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)are acute mucocutaneous reactions associated with poor prognosis. The treatment is mainly symptomatic, based on supportive care. Until now, several curative treatments have been proposed without evidence of effectiveness.Objectives To evaluate the effect of ciclosporin on SJS and TEN after a short series had suggested a benefit.Methods We conducted an open, phase II trial to determine the safety and possible benefit of ciclosporin. Among the 45 consecutive patients admitted for SJS /TEN from March 2005 to September 2007, 29 fulfilled inclusion criteria. Ciclosporin was administered orally (3 mg kg)1 daily for 10 days) and tapered over a month. Clinical and biological evaluations were performed sequentially. Predicted death rate was estimated with a validated prognostic score (SCORTEN).Results Twenty-nine patients were included at a mean +/- SD of 2.8 +/- 1.8 days after onset. The final diagnosis was SJS (n = 10), SJS ⁄TEN overlap (n = 12) and TEN(n = 7). One month of treatment was completed in 26. Ciclosporin was stopped after more than 10 days in three cases for side-effects including posterior leucoencephalopathy (n = 1), neutropenia (n = 1) and nosocomial pneumopathy(n = 1). Ciclosporin dosage was tapered earlier than scheduled in two cases for alteration in renal function. The prognostic score predicted 2.75 deaths; none occurred (P = 0.1). Mean epidermal detachment remained stable in 18 of 29 cases (62%). The mean ± SD hospital stay was 16.2 +/- 9.1 days.Conclusions Both the death rate and the progression of detachment seemed lower than expected, suggesting a possible usefulness of ciclosporin in SJS and TEN that needs to be confirmed.

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

Drug-induced toxic epidermal necrolysis (TEN), also known as Lyell's syndrome, is a life-threatening drug reaction characterized by extensive destruction of the epidermis and mucosal epithelia. The eyes are typically involved in TEN. At present, the disease has a high mortality rate. Conceptually, TEN and the Stevens-Johnson syndrome are closely related, although their severity and outcome are different. Distinguishing TEN from severe forms of erythema multiforme relies on consideration of aetiological, clinical and histological characteristics. The current understanding of the pathomechanism of TEN suggests that keratinocytes are key initiator cells. It is probable that the combined deleterious effects on keratinocytes of both the cytokine tumour necrosis factor (TNF)-alpha and oxidative stress induce a combination of apoptotic and necrotic events. As yet, there is no evidence indicating the superiority of monotherapy with corticosteroids, ciclosporin (cyclosporine) or intravenous immunoglobulins over supportive care only for patients with TEN. However, the current theory of TEN pathogenesis supports the administration of a combination of antiapoptotic/antinecrotic drugs (e.g. anti-TNF-alpha antibodies plus N-acetylcysteine) targeting different levels of the keratinocyte failure machinery.

Update on the management of antibiotic allergy

Drug allergy to antibiotics may occur in the form of immediate or non-immediate (delayed) hypersensitivity reactions. Immediate reactions are usually IgE-mediated whereas non-immediate hypersensitivity reactions are usually non-IgE or T-cell mediated. The clinical manifestations of antibiotic allergy may be cutaneous, organ-specific (e.g., blood dyscracias, hepatitis, interstitial nephritis), systemic (e.g., anaphylaxis, drug induced hypersensitivity syndrome) or various combinations of these. Severe cutaneous adverse reactions manifesting as Stevens Johnson syndrome or toxic epidermal necrolysis (TEN) may be potentially life-threatening. The management of antibiotic allergy begins with the identification of the putative antibiotic from a detailed and accurate drug history, complemented by validated in-vivo and in-vitro allergological tests. This will facilitate avoidance of the putative antibiotic through patient education, use of drug alert cards, and electronic medical records with in-built drug allergy/adverse drug reaction prescription and dispensing checks. Knowledge of the evidence for specific antibiotic cross-reactivities is also important in patient education. Apart from withdrawal of the putative antibiotic, immunomodulatory agents like high-dose intravenous immunoglobulins may have a role in TEN. Drug desensitization where the benefits outweigh the risks, and where no alternative antibiotics can be used for various reasons, may be considered in certain situations. Allergological issues pertaining to electronic drug allergy alerts, computerized physician prescriptions and decision support systems, and antibiotic de-escalation in antimicrobial stewardship programmes are also discussed.

Pathogenesis and recent therapeutic trends in Stevens-Johnson syndrome and toxic epidermal necrolysis

OBJECTIVE

To review the current pathophysiologic mechanisms and recent therapeutic trends in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

DATA SOURCES

A MEDLINE search for SJS and TEN in combination with Fas, Fas ligand (FasL), cytotoxic T cells, intravenous immunoglobulin, and cyclosporine for articles published in English during 1966 to 2006.

STUDY SELECTION

Information was derived from original research articles and reviews published in peer-reviewed journals.

RESULTS

The hallmark of SJS and TEN is epidermal cell apoptosis, which may be mediated through keratinocyte Fas-FasL interaction or through cytotoxic T-cell release of perforin and granzyme B. Whereas systemic corticosteroid therapy showed contradictory results, intravenous immunoglobulin (IVIG) and cyclosporine have shown promising outcomes. IVIG contains anti-Fas antibodies that can abrogate apoptosis when preincubated with keratinocytes. Most studies on IVIG in SJS and TEN reported improvement in arresting disease progression and reduction in time to skin healing. Because of variations among studies, the findings cannot be optimally compared. In general, mortality varied from 0% to 12% in studies that supported the use of IVIG and 25% to 41.7% in those that did not demonstrate a beneficial effect. Cyclosporine inhibits CD8 activation and thus may reduce epidermal destruction. Relatively few case reports and 1 case series have been published regarding the use of cyclosporine in SJS and TEN. In general, cyclosporine was associated with a significant improvement in time to disease arrest and to complete reepithelization, with no reported fatalities.

CONCLUSIONS

Both IVIG and cyclosporine have been associated with enhanced healing and better survival through inhibition of apoptosis. Multicenter, randomized, placebo-controlled trials using a standardized design are needed to validate these findings.

Analytical quantification of the inflammatory cell infiltrate and CD95R expression during treatment of drug-induced toxic epidermal necrolysis

The treatment of drug-induced toxic epidermal necrolysis (TEN) remains unsatisfactory. Intravenous immunoglobulins (IVIg) and intravenous cyclosporin A (CsA) have shown some efficacy in short series of patients. We assessed the effects of IVIg and CsA on TEN lesional and apparently uninvolved skin using standard histology and immunohistochemistry. Cutaneous biopsies were taken from necrotic and clinically uninvolved TEN skin at admission (D1) before any treatment, and after a 5-day treatment (D5). Two IVIg-treated patients (0.75 g/kg/day), two CsA-treated patients (5 mg/kg/day) and two control patients only receiving supportive care were compared. Biopsies were examined by standard histology and immunohistochemistry using antibodies directed to CD68 antigen (macrophages), CD45R0 antigen (activated T lymphocytes), Factor XIIIa (dermal dendrocytes) and the CD95 receptor (apoptosis marker). The different cell densities were evaluated by computerized image analysis. The clinical outcomes with the different treatments were also recorded. There was no obvious difference in the duration of hospitalization in intensive care unit between the three groups but one patient passed away in each of the IVIg- and CsA-groups. At D5, no differences were found between the three groups in the histological and clinical rate of re-epithelialization, and in the evolution of T lymphocyte, macrophage and dendrocyte densities in the epidermis and dermis. However, the expression of the CD95 receptor was similarly and strongly abated at D5 in the epidermis of IVIg- and CsA-treated patients, while it was conversely increased in the two patients under supportive care only. Such a difference was found both in necrotic and uninvolved sites. IVIg and CsA treatments thus appeared to exert no obvious effect on the inflammatory infiltrate, but both abated the expression of the CD95 receptor in the skin of TEN patients. This effect did not seem sufficient to fully reverse the clinical evolution of the disease. It is inferred that IVIg and CsA do not completely abate the TEN process.

Toxic epidermal necrolysis: current evidence, practical management and future directions

Toxic epidermal necrolysis (TEN) is a rare disorder characterized by extensive epidermal death. Almost all cases appear to be caused by an idiosyncratic drug reaction. Proposed pathogenic mechanisms are conflicting, and the evidence for the benefits of individual treatments is inadequate, and in some cases contradictory. The mortality rate remains high. We review the literature pertaining to the pathogenesis of TEN and drug reactions in general. The rationale for therapeutic interventions, together with reported evidence of efficacy, are considered. We present a composite model of TEN, based on previous work and suggested pathogeneses of TEN, mechanisms of drug reactions and reported cytotoxic lymphocyte (CTL) cytolytic pathways. In this system, TEN, like some other cutaneous drug eruptions, is an HLA class I-restricted, specific drug sensitivity, resulting in clonal expansion of CD8+ CTLs. Cytotoxicity is mediated by CTL granzyme and possibly death receptor (DR) ligand (DR-L), probably Fas ligand (FasL). Particular to TEN, there is then an amplification sequence involving further DR-L expression. FasL is likely to be particularly important but tumour necrosis factor (TNF) may well contribute, via the TNF receptor 1 (TNF-R1) death pathway. Alternatively, we suggest the possibility of upregulation of an antiapoptotic TNF-R1-nuclear factor kappaB pathway, which would proscribe treatments which downregulate this pathway. None of the published data on individual treatment efficacies is sufficiently strong to suggest a definitive single treatment. Currently a multifaceted regimen appears indicated, targeting various likely intermediary mechanisms, including elimination of residual drug, immunosuppression, inhibition of DR pathways, general antiapoptotic strategies, and aggressive supportive care. Particular attention has been directed at avoiding potential conflicts between different treatments and avoiding agents that theoretically might have a net proapoptotic rather than antiapoptotic effect. Nursing on a specialized unit is of paramount importance.

The Use of Systemic Immune Moderators in Dermatology: An Update

In addition to corticosteroids, dermatologists have access to an array of immunomodulatory therapies. Azathioprine, cyclophosphamide, methotrexate, cyclosporine, and mycophenolate mofetil are the systemic immunosuppressive agents most commonly used by dermatologists. In addition, new developments in biotechnology have spurred the development of immunobiologic agents that are able to target the immunologic process of many inflammatory disorders at specific points along the inflammatory cascade. Alefacept, efalizumab, etanercept, and infliximab are the immunobiologic agents that are currently the most well known and most commonly used by dermatologists. This article reviews the pharmacology, mechanism of action, side effects, and clinical applications of these therapies.

Novel Treatments for Drug-Induced Toxic Epidermal Necrolysis (Lyell’s Syndrome)

Drug-induced toxic epidermal necrolysis (TEN) is a life-threatening disease characterized by extensive destruction of the epidermis. It apparently results from the formation of specific toxic drug metabolites by the keratinocytes. The mortality rate which averages 25-30% is mainly due to secondary septicemia, and to ionic and metabolic disturbances following loss of epidermal integrity. Apoptosis is the likely mechanism leading to massive keratinocyte death in TEN. Dysregulations in the tumor necrosis factor-alpha (TNF-alpha) pathway, CD95 system (Fas ligand, CD95L; Fas receptor, CD95R) and calcium homeostasis in the epidermis are involved in this apoptotic process. An active role has also been ascribed to T lymphocytes, macrophages and factor XIIIa-positive dermal dendrocytes. Despite progress, treatment of TEN remains controversial. In the past, systemic glucocorticoids were used in order to target the inflammatory reaction in TEN. However, there was no evidence for improvement of the healing process, while corticosteroids worsened the prognosis by increasing the risk of septicemia. Only a few cases have been treated with other drugs including cyclophosphamide, pentoxyfilline, thalidomide, anti-TNF-alpha antibodies and cyclosporin A. In the recent past, some TEN patients were treated with intravenous human immunoglobulins (IVIG). The rationale for such a treatment was to block the CD95 system on keratinocytes. The early promising clinical results of IVIG treatment in TEN were subsequently challenged. This review compares the effectiveness and drawbacks of the major drugs presently used in TEN treatment. Some future prospects in TEN management are also discussed.

Cyclosporine and tacrolimus in dermatology

Immune modulators are being used with increasing frequency in dermatology. This article reviews two such agents, cyclosporine and tacrolimus. Discussion emphasizes the pharmacology, side effects, and uses of these two drugs in dermatologic disorders.

Drug-induced Stevens-Johnson syndrome/toxic epidermal necrolysis

Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) is a rare (occurring in approximately 2 to 3 people/million population/year in Europe and the US), life-threatening, intolerance reaction of the skin. It is most often caused by drugs (most commonly sulfonamides, nonsteroidal anti-inflammatory drugs, antimalarials, anticonvulsants, and allopurinol). SJS/TEN is characterized by a macular exanthema ('atypical targets') which focusses on the face, neck, and the central trunk regions. Lesions show rapid confluence, a positive Nikolsky's sign, and quickly result in widespread detachment of the epidermis and erosions. Mucosal, conjunctival, and anogenital mucous membranes are prominently involved. Histopathology shows satellite cell necrosis in the early stages progressing to full thickness necrosis of the epidermis, contrasting with rather inconspicuous inflammatory infiltrates of the dermis. Damage to the skin is thought to be mediated by cytotoxic T lymphocytes and mononuclear cells which induce apoptosis in keratinocytes expressing drug-derived antigens at their surfaces. No guidelines for the treatment of SJS/TEN exist since no controlled clinical trials have ever been performed. The controversy over whether systemic corticosteroids should be used to curtail progression is still unresolved; while many authors agree that corticosteroids do in fact suppress progression, it is obvious that they also greatly enhance the risk of infection, the complication which most frequently leads to a fatal outcome. It appears reasonable to only administer corticosteroids in the phase of progression and to withdraw them as soon as possible, and to add antibacterials for prophylaxis. Recently, in a small series of patients, intravenous immunoglobulins were presumed to be effective by the blockade of lytic Fas ligand-mediated apoptosis in SJS/TEN. However, these results have to be confirmed by large clinical trials. Supportive treatment and monitoring of vital functions is of utmost importance in SJS/TEN, and out-patient treatment is unacceptable. Recovery is usually slow, depending on the extent and severity and the presence of complications, and may take 3 to 6 weeks. Skin lesions heal without scars as a rule, but scarring of mucosal sites is a frequent late complication, potentially leading to blindness, obliteration of the fornices and anogenital strictures. There is no reliable laboratory test to determine the offending drug; diagnosis rests on the patient's history and the empirical risk of drugs to elicit skin SJS/TEN. Provocation tests are not indicated since re-exposure is likely to elicit a new episode of SJS/TEN of increased severity.

Treatment of toxic epidermal necrolysis with cyclosporin A

BACKGROUND

Toxic epidermal necrolysis (TEN) is a severe skin disorder characterized by separation of the dermal-epidermal junction, as is observed in second-degree superficial burns. It has been proposed that immunosuppressive treatment may improve prognosis of patients with TEN.

METHODS

We report here a case series of patients with TEN treated with cyclosporin A (CSA) without other concomitant immunosuppressive agent. These patients (n = 11) were consecutively admitted to our Intensive Care Burn Unit because of severe TEN, involving a large body surface area (83 +/- 17% [mean +/- SD], median, 90%; range, 35-96%) and were treated with CSA 3 mg/kg per day enterally every 12 hours. We compared the series of patients treated with CSA with a historical series of patients admitted to our Intensive Care Burn Unit before CSA was introduced as part of the treatment protocol These patients (n = 6) were treated with cyclophosphamide (150 mg i.v. every 12 hours) and different doses of corticosteroids (> or =1 mg/kg per day of 6-methyl-prednisolone). Both groups of patients were similar in regard to age, delay from onset of disease to Intensive Care Burn Unit admission, and body surface area involved.

RESULTS

Time from the onset of skin signs to arrest of the disease progression (1.4 +/- 0.3 days, vs. 3.6 +/- 1.5 days) and to complete reepithelialization (12.0 +/- 3.6 days, vs. 17.6 +/- 3.1 days) was significantly shorter in patients treated with CSA compared with those treated with cyclophosphamide and corticosteroids (p = 0.0002, and p = 0.0058, respectively). Significantly fewer patients in the CSA group had > or =4 organs failing (2 of 11 vs. 3 of 6, respectively, p = 0.029), had severe leukopenia (<1,000 cells/microL) (0 of 11 vs. 4 of 6, respectively, p = 0.006), or died (3 of 6 vs. 0 of 11, respectively, p = 0.0029).

CONCLUSION

We conclude that immunosuppressive treatment with CSA is safe and is associated with a rapid reepithelialization rate and a low mortality rate in patients with severe TEN. Our data suggest that this regimen could be more effective than treatment with cyclophosphamide and corticosteroids. Prospective controlled trials are required to test the hypothesis that CSA is more effective than cyclophosphamide or other immunosuppressive regimens for the treatment of TEN.

Treatment of severe drug eruptions

Severe drug eruptions are rare, life-threatening events. The management begins with the withdrawal of the suspect drug(s). We recently confirmed that an earlier withdrawal of drugs with short elimination half-life was associated with a better survival of patients with Stevens-Johnson syndrome (SJS) or toxic epidermal necrolysis (TEN). In cases of "acute skin failure" (exfoliative dermatitis, extensive SJS or TEN), management of patients must be undertaken in specialized intensive care units or in burn units. The main principles of symptomatic therapy are the same as for major burns: warming of the environment, correction of electrolyte disturbances, high caloric intake, and prevention of sepsis. The suspected immunologic orgin of drug eruptions prompted the use of corticosteroids, immunosuppressive drugs, and anti-cytokines. Systemic corticosteroids are useful in "hypersensitivity syndrome" when visceral lesions depend on infiltration by activated cosinophils. Systemic corticosteroids were shown to be deleterious in cases of advanced TEN. Their potential usefulness at earlier stages of SJS or TEN remains controversial. High intravenous doses of cyclophosphamide or oral cyclosporin have been administered to a few patients with TEN, most often following ineffective treatment with corticosteroids for 1 to 5 days. It remains doubtful that the progression of the lesions was shortened. A few patients appeared to benefit from treatment with pentoxifyllin, a drug suppressing the production of TNF. Thalidomide, another suppressor of TNF production, significantly increased the death rate when tested in a double-blind placebo controlled trial in patients with early TEN. High dose intravenous immunoglobulins were used in 10 patients with TEN on the basis of their ability to inhibit fas-fas ligand mediated apoptosis. The potential benefit of this treatment needs confirmation by further studies. Patients and their first degree relatives should be advised to avoid the responsible drug and chemically related compounds. Regulatory agencies should be notified of such cases.

Immunosuppressive agents in dermatology. An update

Azathioprine, cyclophosphamide, methotrexate, and cyclosporine are the immunosuppressive agents most commonly used by dermatologists. Azathioprine has a relatively good safety profile and is therefore often preferred for the treatment of chronic eczematous dermatitides and bullous disorders. Awareness of the role of genetic polymorphisms in its metabolism can increase the efficacy and safety of this drug. Cyclophosphamide is an antimetabolite that has a more rapid onset of immunosuppressive effect than azathioprine, but has significant short-term and long-term toxicity. It is of use in fulminant, life-threatening cutaneous disease. Methotrexate is an antimetabolite that has significant anti-inflammatory activity. Despite its hepatotoxicity, its role in inflammatory dermatoses is broadening. Likewise, the role of cyclosporine is being expanded. This drug has potent T-cell inhibitory effects secondary to interference with intracellular signal transduction. Given the evidence for cumulative renal toxicity, it currently has a role in the short-term treatment of refractory psoriasis and atopic dermatitis, as well as in select inflammatory dermatoses. Familiarity with disease-specific clinical efficacy, side-effect profile, and dosage allows the successful and judicious use of these drugs in dermatologic disorders.