Long-term ocular complication of Stevens-Johnson syndrome

Improvement of the Ocular Prognosis of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A National Survey in Japan

PURPOSE

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.

DESIGN

Retrospective, national trend survey.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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

Relationship between Atopic Disease and Acute Ocular and Systemic Outcomes in Patients with Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis

OBJECTIVE

To describe the relationship between history of atopic disease on systemic and ocular manifestations of Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis (SJS/TEN).

METHODS

Retrospective chart review of patients with SJS/TEN patients. Those with and without prior atopic diagnosis were compared.

RESULTS

In total, 200 patients with SJS/TEN were identified. A total of 23 patients also had an atopic diagnosis. Four, 10, and 18 had atopic dermatitis, allergic rhinitis, and asthma respectively. Acute ocular severity was significantly worse in the atopic cohort. No significant differences in overall systemic severity of SJS or mortality were found between the atopic and non-atopic cohorts. Compared to our hospital system's general population, prevalence of an atopic diagnosis was significantly higher in those with SJS/TEN.

CONCLUSION

Patients with a history of an atopic diagnosis appear to have more significant acute ocular involvement during their SJS/TEN hospitalization. Atopic conditions appear to occur more frequently in the SJS/TEN population compared to the general population.

Long-Term Benefits of Tear Exchangeable Limbal-Rigid Contact Lens Wear Therapy in Stevens-Johnson Syndrome Cases

OBJECTIVES

To evaluate the long-term benefits of tear-exchangeable, limbal-rigid contact lens (CL) wear therapy in patients with Stevens-Johnson syndrome (SJS)-associated ocular sequelae.

METHODS

This retrospective study evaluated 50 eyes of 41 SJS patients (15 men and 26 women) who underwent limbal-rigid CL wear therapy for more than 2 years post fitting. Ocular sequelae (i.e., conjunctival hyperemia, corneal neovascularization, and upper tarsus scarring) before fitting and at 3 months, 6 months, 12 months, and annually after initiating CL wear therapy were evaluated and then graded on a severity score (range: 0-3, maximum score: 3). Moreover, visual acuity (VA) at immediately post initiating CL wear therapy was evaluated.

RESULTS

The mean follow-up period was 4.3±1.1 years. Compared with before fitting, the mean conjunctival hyperemia score improved from 1.14 to 0.86 at 3 months of CL wear therapy ( P <0.01) and was maintained thereafter; the mean corneal neovascularization score improved from 2.10 to 1.98 at 3 months of CL wear therapy, with no deterioration of the score observed in all cases at the final follow-up examination, and mean VA (log of minimum angle of resolution) improved from 1.60 to 1.04 at immediately post initiating CL wear therapy ( P <0.01).

CONCLUSIONS

Limbal-rigid CL wear therapy can provide long-term ocular surface stabilization and improved VA in SJS patients.

Multi-state model for predicting ocular progression in acute Stevens-Johnson syndrome/toxic epidermal necrolysis

This study aimed to clarify the etiologic factors predicting acute ocular progression in SJS/TEN, and identify patients who require immediate and intensive ophthalmological treatment. We previously conducted two Japanese Surveys of SJS/TEN (i.e., cases arising between 2005-2007 and between 2008-2010), and obtained the medical records, including detailed dermatological and ophthalmological findings, of 230 patients. Acute ocular severity was evaluated as none, mild, severe, and very severe. A multi-state model assuming the Markov process based on the Cox proportional hazards model was used to elucidate the specific factors affecting the acute ocular progression. Our findings revealed that of the total 230 patients, 23 (24%) of 97 cases that were mild at initial presentation worsened to severe/very severe. Acute ocular progression developed within 3 weeks from disease onset. Exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) and younger patient age were found to be statistically significant for the progression of ocular severity from mild to severe/very severe [hazard ratio (HR) 3.83; 95% confidence interval (CI) 1.48 to 9.91] and none to severe/very severe [HR 0.98; 95% CI 0.97 to 0.99], respectively. The acute ocular severity score at worst-condition was found to be significantly correlated with ocular sequelae. Thus, our detailed findings on acute ocular progression revealed that in 24% of SJS/TEN cases with ocular involvement, ocular severity progresses even after initiating intensive treatment, and that in younger-age patients with a history of exposure to NSAIDs, very strict attention must be given to their ophthalmological appearances.

Physical and Psychological Recovery Following Toxic Epidermal Necrolysis: A Patient Survey

Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are acute, life-threatening diseases that cause sloughing of the skin and mucous membranes. Despite improved survival rates, few studies focus on long-term outcomes. We conducted a single-center review of all patients with SJS/TEN admitted from January 2008-2014. SJS/TEN survivors were invited to participate in the validated Veterans RAND 12 Item Health Survey (VR-12) to assess health related quality of life using a mental health composite score (MCS) and physical health component score (PCS). The sample was compared to US norms using one sample two tailed t-tests. A second questionnaire addressed potential long-term medical complications related to SJS/TEN. Of 81 treated subjects, 24 (30%) long-term survivors responded. Participants identified cutaneous sequelae most frequently (79%), followed by nail problems (70%), oral (62%) and ocular (58%) sequalae. Thirty-eight percent rated their quality of life to be "unchanged" to "much better" since their episode of SJS/TEN. The average PCS score was lower than US population norms (mean: 36 vs. 50, p=0.006), indicating persistent physical sequelae from SJS/TEN. These results suggest that SJS/TEN survivors continue to suffer from long-term complications that impair their quality of life and warrant ongoing follow-up by a multidisciplinary care team.

The distribution of conjunctival goblet cells in mice

PURPOSE

To evaluate the density and distribution of conjunctival goblet cells in mice without clinical evidence of ocular surface diseases.

METHODS

Immediately after euthanasia of C57BL/6 wild-type mice, the eyes including eyelids were removed and fixed in paraformaldehyde. Entire eyeballs and eyelids were cut in series along the sagittal axis from nasal to temporal on a microtome and then stained with Periodic Acid-Schiff acid to visualize the goblet cells. At each section stained in this way, the conjunctival goblet cells of the entire upper and lower lid conjunctiva were counted by light microscopy. Additional (transmission electron microscopy) (TEM)-Analysis on ultrathin sections was performed to evaluate morphological differences.

RESULTS

The total number of conjunctival goblet cells differs markedly between individual animals. Categorisation into upper eyelid (UL) and lower eyelid (LL) and into regions (nasal, middle, temporal) revealed a significant increase of goblet cells from nasal to temporal in the UL and a significant decrease in the LL.

CONCLUSION

The distribution of conjunctival goblet cells in mice differs considerably from humans and between individual animals. Therefore, precise selection of sampling and methods are needed to obtain comparable data. We recommend to use the middle region of the conjunctiva of UL/LL for goblet cell studies in mice. These findings are of particular interest for dry eye mouse models as well as pharmacological studies on mice with influence on their goblet cells.

Predictive biomarkers for the progression of ocular complications in chronic Stevens-Johnson syndrome and toxic Eeidermal necrolysis

This study aimed to clarify predictive biomarkers of mild and severe ocular complications of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) by examining the cytokines in tears. In 121 chronic-phase SJS/TEN eyes, cytokines in tear samples collected using Schirmer test strips were measured, and ocular sequelae severity was evaluated using an Ocular Surface Grading Score (OSGS) involving 7 components (conjunctivalization, neovascularization, opacification, keratinization, symblepharon, and upper/lower conjunctival-sac shortening), with findings categorized into grades 0–3 (maximum total OSGS: 21). Changes in cytokines between the mild and severe groups (mild: total OSGS of 10 or less, severe: total OSGS of 11 or more), and changes between SJS/TEN cases with and without each of the 7 components, were compared. In the severe group, there was significant upregulation of interleukin (IL)-8 (P < 0.01) and Granzyme B (GrzB) (P < 0.05). IL-8 was significantly upregulated in eyes with conjunctivalization, neovascularization, or opacification, GrzB was upregulated in eyes with keratinization, interferon-γ-inducible protein 10 (IP-10) was downregulated in eyes with conjunctivalization or neovascularization, and IL-1α was upregulated in eyes with opacification (all: P < 0.05). IL-8 and IP-10 was involved in conjunctivalization and neovascularization, while GrzB was involved in keratinization. IL-8 and GrzB in tears may reflect SJS/TEN-related ocular sequelae severity.

Evaluation of chronic ocular sequelae in patients with symblepharon caused by ocular burns

AIM

To evaluate chronic ocular sequelae in patients with symblepharon caused by ocular burns and propose an objective grading system.

METHODS

This was a retrospective, single-center clinical study. Patients with symblepharon caused by ocular burns at least six months later were assessed. Chronic ocular sequelae were classified into 3 categories (eyelid, conjunctiva, and cornea) and 9 chronic ocular sequelae [friction factors, exposure factors, conjunctival hyperemia, length of symblepharon, scope of adhesion, lacrimal area adhesion, loss of the palisades of Vogt (POV), corneal neovascularization, and corneal opacification]. Each ocular sequela was graded from 0 to 3, depending on the increasing severity. The 9 ocular sequelae were evaluated to obtain the total severity score for each eye. The total severity score was defined as Grade I (1-9), Grade II (10-18), and Grade III (19-27). Moreover, the correlation between the severity of chronic ocular sequelae and visual acuity, surgical strategy, and the prognosis was analyzed, respectively.

RESULTS

Cases of 79 eyes with symblepharon caused by ocular burns were included in this study. Of these, 20 (25.32%) were defined as Grade I, 43 (54.43%) as Grade II, and 16 (20.25%) as Grade III. Eyes with a high total severity score had reduced visual acuity, required complicated surgery strategies, and poor prognosis (P<0.001). Multivariate regression analysis showed that the scope of adhesion, corneal opacification, and corneal neovascularization significantly affected visual acuity, surgical strategy, and prognosis (all P<0.001).

CONCLUSION

The evaluation of chronic ocular sequelae enabled the development of an objective grading system for patients with symblepharon caused by ocular burns. This grading system can be applied to guide the treatment and predict the prognosis.

Chronic Ocular Complications of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: The Role of Systemic Immunomodulatory Therapy

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, but potentially blinding diseases that affect the skin and mucous membranes. Although the cutaneous manifestations tend to be self-limited and resolve without sequelae, the chronic ocular complications associated with SJS/TEN can persist despite local therapy. Poor understanding of the underlying pathophysiology and lack of a standardized clinical approach have resulted in a paucity of data in regards to suitable treatment options. Inflammatory cellular infiltration and elevated levels of ocular surface cytokines in the conjunctival specimens of affected patients give credence to an underlying immunogenic etiology. Furthermore, the presence of ongoing ocular surface inflammation and progressive conjunctival fibrosis in the absence of exogenous aggravating factors suggest a possible role for systemic immunomodulatory therapy (IMT). We review in detail the proposed immunogenesis underlying chronic ocular SJS/TEN and the possible utility of systemic IMT.

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.

Management of acute Stevens-Johnson syndrome and toxic epidermal necrolysis utilizing amniotic membrane and topical corticosteroids

PURPOSE

To describe the results of a novel treatment approach to the acute ophthalmic management of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

DESIGN

Retrospective interventional case series.

METHODS

setting: Institutional. study population: Sixteen eyes of 8 patients with acute, biopsy-proven SJS or TEN and significant ophthalmic involvement. interventional procedure(s): Application of amniotic membrane to the ocular surface, either in the operating room or at the bedside, and short-term use of intensive topical corticosteroid medication. main outcome measures: Visual acuity, slit-lamp appearance of the ocular surface, and patients' subjective impression of ocular comfort.

RESULTS

Two patients expired during the hospitalization. Mean follow-up time for the surviving patients was 7.7 months. Four surviving patients in whom the entire ocular surface (ie, the cornea, bulbar and palpebral conjunctiva, and eyelid margins) was treated with amniotic membrane retained visual acuities of 20/40 or better and an intact ocular surface. In contrast, the initial 2 patients in the study who were treated with only a Prokera device or unsutured amniotic membrane sheets, leaving the palpebral conjunctiva and eyelid margins uncovered, developed more significant ocular surface abnormalities, and 1 developed a corneal perforation.

CONCLUSIONS

Amniotic membrane coverage of the ocular surface in its entirety coupled with the use of intensive short-term topical corticosteroids during the acute phase of SJS and TEN is associated with the preservation of good visual acuity and an intact ocular surface. Partial amniotic membrane coverage of the ocular surface may not serve to minimize the cicatrizing ocular sequelae of SJS and TEN as effectively as complete coverage.

Successful treatment of Stevens-Johnson syndrome with steroid pulse therapy at disease onset

PURPOSE

To evaluate the visual prognosis of patients with Stevens-Johnson syndrome (SJS) and its severe variant, toxic epidermal necrolysis (TEN), followed by general and topical high-dose corticosteroids administration from disease onset.

DESIGN

Prospective, observational case series.

METHODS

Between May 1, 2003 and June 30, 2005, we enrolled 5 patients with SJS or TEN with ocular complications at the acute stage. Intravenous pulse therapy with methylprednisolone (steroid pulse therapy; 500 or 1000 mg/day for 3 to 4 days) was initiated within 4 days from disease onset. Topically, 0.1% betamethasone was applied over 5 times daily for at least 2 weeks. Visual acuity (VA) and slit-lamp microscopic appearance 1 year from disease onset were evaluated.

RESULTS

At the first examination, corneal or conjunctival epithelial defects and pseudomembranous conjunctivitis were present in all cases. Skin eruptions dramatically improved after steroid pulse therapy. Although ocular inflammation increased for several days, pseudomembranes disappeared and corneal and conjunctival epithelium regenerated within 6 weeks. At the chronic stage, all eyes had clear corneas with the palisades of Vogt (POV), implying the presence of corneal epithelial stem cells. Best-corrected VA was 20/20 or better in all eyes. Five eyes showed superficial punctate keratopathy. No eye had cicatricial changes except for 1 with slight fornix shortening. No significant adverse effects of steroid occurred during all clinical courses.

CONCLUSIONS

Steroid pulse therapy at disease onset is of great therapeutic importance in preventing ocular complications. Topical betamethasone also shows great promise for preventing corneal epithelial stem cell loss in the limbal region and cicatricial changes.

New grading system for the evaluation of chronic ocular manifestations in patients with Stevens-Johnson syndrome

PURPOSE

To evaluate and grade the extent and severity of chronic ocular manifestations in Stevens-Johnson syndrome (SJS).

DESIGN

Prospective multicenter case series.

PARTICIPANTS

We enrolled 73 patients (138 eyes) with SJS seen between April 2003 and March 2005 at 3 tertiary referral centers.

METHODS

Patients with a confirmed history of SJS and chronic ocular complications that persisted for at least 1 year from the onset of SJS were included. Their detailed medical history and ophthalmic examination results were recorded on an itemized data collection form. Complications were categorized as corneal, conjunctival, and eyelid complications, and 13 components were evaluated and graded on a scale from 0 to 3 according to their severity.

MAIN OUTCOME MEASURES

These were broadly classified as corneal (superficial punctate keratopathy, epithelial defect, loss of the palisades of Vogt, conjunctivalization, neovascularization, opacification, keratinization), conjunctival (hyperemia, symblepharon formation), and eyelid (trichiasis, mucocutaneous junction involvement, meibomian gland involvement, punctal damage) complications.

RESULTS

The most severely affected complication components were loss of the palisades of Vogt (114 eyes; 82.6%) and meibomian gland involvement (102 eyes; 73.9%). Visual acuity in 74 of the 138 eyes (53.6%) was worse than 20/200. The severity of corneal, conjunctival, and eyelid complications was significantly correlated with visual loss. All 13 complications were correlated significantly with logarithm of the minimum angle of resolution (logMAR) visual acuity; the correlation coefficient (R) ranged from 0.359 to 0.810 (P<0.0001); for corneal epithelial defects, R was 0.169 (P = 0.0473). Eyes with a higher total score for the 3 complication categories had poorer vision (R = 0.806; P<0.0001). Multivariate regression analysis showed that corneal neovascularization, opacification, keratinization, and cataracts significantly affected logMAR visual acuity (P<0.0001, P<0.0001, P = 0.0142, P = 0.0375, respectively).

CONCLUSIONS

The authors describe a new method for grading the extent and severity of ocular involvement in patients with SJS and demonstrate that the severity of ocular involvement is correlated significantly with the final visual outcome. This new grading system provides a more objective method for evaluating SJS patients and may be adapted for use in other cicatricial ocular surface diseases.

Long-term follow-up of patients treated for toxic epidermal necrolysis

Patient outcomes concerning toxic epidermal necrolysis (TEN) have improved over the years as a better understanding of the pathophysiology of the illness has been gained and enhancements have been made in the care of the acutely ill. With increase in survival, long-term complications these patients experience are beginning to be recognized. In this study, we analyzed the outcomes of a cohort of TEN survivors treated at our burn unit and sought to determine the impact of clinical variables from the initial hospitalization on mortality after discharge. We performed a retrospective review of data from patients with TEN treated at our burn unit from March 1993 to September 2002. Follow-up data on new health problems were collected on patients who were alive at discharge via questionnaire. Survival was estimated using the Kaplan-Meier method with Cox regression model. During the study period, of the 64 patients treated for TEN, 46 survived. After discharge, 15 patients died, whereas the remaining 31 patients continued to suffer from ocular (54%), skin (81%), and renal (23%) problems. Median survival for the whole cohort has not been reached, with an estimated 5-year survival of 65%. No patient in either group had a TEN recurrence. Seventy-nine percent of the patients with ocular involvement in the acute phase of TEN had long-term ocular complications, and 73% of patients with mucosal involvement had persistent mucosal lesions. Five individual factors were found to be predictors of postdischarge mortality on univariate analysis: age at diagnosis of TEN>or=60 years, SCORTEN 3 to 6, % maximal TBSA slough>or=50%, days from onset of symptoms to admission to a burn unit>or=5 days, and presence of multiple comorbidities at diagnosis of TEN. In multivariate analysis, only SCORTEN of 3 to 6 (P=.003) and days to admission>or=5 (P=.027) maintained significance as predictors of mortality and may be used to heighten surveillance during postdischarge care of patients with TEN.

Intravenous Immunoglobulin for Treatment of Toxic Epidermal Necrolysis

We report three female patients suffering from toxic epidermal necrolysis, with 30% to 70% epidermal detachment. Alleged causative agents were dipyrone, dibenzazepine, and allopurinol. All patients were treated by intravenous immunoglobulins (IVIG) and survived without further complications, although poor prognostic factors such as concomitant diabetes, large areas of epidermal detachment, and pancytopenia were present. We report these cases with emphasis on the concept that prompt diagnosis, withdrawal of causative drugs, and immediate treatment are imperative for the favorable outcome of the disease. Our patients can be added to the list of those patients who were successfully treated by IVIG, as indicated in this review of the literature.

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.