Stevens-Johnson Syndrome | Stephen Foster, MD

Background

Stevens-Johnson syndrome (SJS) is an immune-complex–mediated hypersensitivity complex that typically involves the skin and the mucous membranes. While minor presentations may occur, significant involvement of oral, nasal, eye, vaginal, urethral, gastrointestinal, and lower respiratory tract mucous membranes may develop in the course of the illness. GI and respiratory involvement may progress to necrosis. Stevens-Johnson syndrome is a serious systemic disorder with the potential for severe morbidity and even death.

The syndrome was first described in 1922, when the American pediatricians Albert Mason Stevens and Frank Chambliss Johnson reported the cases of 2 boys aged 7 and 8 years with "an extraordinary, generalized eruption with continued fever, inflamed buccal mucosa, and severe purulent conjunctivitis." Both cases had been misdiagnosed by primary care physicians as hemorrhagic measles.

Erythema multiforme (EM), originally described by von Hebra in 1866, was part of the differential diagnosis in both cases but was excluded because of the "character of skin lesions, the lack of subjective symptoms, the prolonged high fever, and the terminal heavy crusting." Despite the presence of leukopenia in both cases, Stevens and Johnson in their initial report suspected an infectious disease of unknown etiology as the cause.

In 1950, Thomas divided EM into 2 categories: erythema multiforme minor (von Hebra) and erythema multiforme major (EMM). Since 1983, erythema multiforme major and Stevens-Johnson syndrome had been considered synonymous.

In the 1990s, however, Bastuji and Roujeau each proposed that erythema multiforme major and Stevens-Johnson syndrome are 2 distinct disorders.^[1] They suggested that the denomination of erythema multiforme should be restricted to patients with typical targets or raised edematous papules, with or without mucosal involvement. This clinical picture is in accordance with the original description by von Hebra.

Bastuji and Roujeau further proposed that the denomination of Stevens-Johnson syndrome should be used for a syndrome characterized by mucous membrane erosions and widespread small blisters that arise on erythematous or purpuric maculae that are different from classic targets.

According to this clinical classification, erythema multiforme major and Stevens-Johnson syndrome could be 2 distinct disorders with similar mucosal erosions, but different patterns of cutaneous lesions. This hypothesis is supported further by a strong correlation between clinical classification and the probable cause.

Conversely, several investigators propose that Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN) represent the same disease at different levels of severity. A unifying classification of "acute disseminated epidermal necrosis" or "exanthematic necrolysis" has been suggested.

Although several classification schemes have been reported, the simplest breaks the disease down as follows^[2] :

• Stevens-Johnson syndrome - A "minor form of TEN," with less than 10% body surface area (BSA) detachment
• Overlapping Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) - Detachment of 10-30% BSA
• Toxic epidermal necrolysis - Detachment of more than 30% BSA

An argument against this unifying concept was that HSV infection had been described as a frequent cause of Stevens-Johnson syndrome/erythema multiforme major but not of toxic epidermal necrolysis. However, reports showed that HSV infection has not been related to Stevens-Johnson syndrome, and suggested that clinical manifestations and pathology results support the linking of Stevens-Johnson syndrome and toxic epidermal necrolysis, and their differentiation from erythema multiforme.

Various etiologic factors (eg, infection, drugs, malignancies) have been implicated as causes of Stevens-Johnson syndrome. However, as many as half of cases are idiopathic. There is strong evidence for a genetic predisposition to Stevens-Johnson syndrome provoked by certain drugs. (See Etiology.)

There are no specific laboratory studies (other than biopsy) that can definitively establish the diagnosis of Stevens-Johnson syndrome (see Clinical and Workup). No specific treatment of Stevens-Johnson syndrome is noted; most patients are treated symptomatically. In principle, the symptomatic treatment of patients with Stevens-Johnson syndrome does not differ from the treatment of patients with extensive burns. Withdrawal of the suspected offending agent is critically important. Immunomodulatory treatment is controversial. (See Treatment.)

For patient education information, see the Skin, Hair, and Nails Center, as well as Life-Threatening Skin Rashes.

Pathophysiology

An idiosyncratic, delayed hypersensitivity reaction has been implicated in the pathophysiology of Stevens-Johnson syndrome. Certain population groups appear more susceptible to develop Stevens-Johnson syndrome than the general population. Slow acetylators, patients who are immunocompromised, and patients with brain tumors undergoing radiotherapy with concomitant antiepileptics are among those at most risk.

Slow acetylators are people whose liver cannot completely detoxify reactive drug metabolites. For example, patients with sulfonamide-induced toxic epidermal necrolysis have been shown to have a slow acetylator genotype that results in increased production of sulfonamide hydroxylamine via the P-450 pathway. These drug metabolites may have direct toxic effects or may act as haptens that interact with host tissues, rendering them antigenic.^{[3, 4]}

Antigen presentation and production of tumor necrosis factor (TNF)–alpha by the local tissue dendrocytes results in the recruitment and augmentation of T-lymphocyte proliferation and enhances the cytotoxicity of the other immune effector cells.^[5] A "killer effector molecule" has been identified that may play a role in the activation of cytotoxic lymphocytes.^[6] The activated CD8+ lymphocytes, in turn, can induce epidermal cell apoptosis via several mechanisms, which include the release of granzyme B and perforin.

In 1997, Inachi et al demonstrated perforin-mediated apoptosis in patients with Stevens-Johnson syndrome.^[7] Perforin, a pore-making monomeric granule released from natural killer cells and cytotoxic T lymphocytes, kills target cells by forming polymers and tubular structures not unlike the membrane attack complex of the complement system.

Apoptosis of keratinocytes can also take place as a result of ligation of their surface death receptors with the appropriate molecules. Those can trigger the activation of the caspase system, leading to DNA disorganization and cell death.^[8]

Apoptosis of keratinocytes can be mediated via direct interaction between the cell-death receptor Fas and its ligand. Both can be present on the surfaces of the keratinocytes. Alternatively, activated T-cells can release soluble Fas ligand and interferon-gamma, which induces Fas expression by keratinocytes.^[2] Researchers have found increased levels of soluble Fas ligand in the sera of patients with SJS/TEN before skin detachment or onset of mucosal lesions.^[9]

The death of keratinocytes causes separation of the epidermis from the dermis. Once apoptosis ensues, the dying cells provoke recruitment of more chemokines. This can perpetuate the inflammatory process, which leads to extensive epidermal necrolysis.^[10]

Etiology

Various etiologic factors have been implicated as causes of Stevens-Johnson syndrome. Drugs most commonly are blamed. The 4 etiologic categories are as follows:

• Infectious
• Drug-induced
• Malignancy-related
• Idiopathic

Stevens-Johnson syndrome is idiopathic in 25-50% of cases. Drugs and malignancies are most often implicated as the etiology in adults and elderly persons. Pediatric cases are related more often to infections.

Infectious causes

Viral diseases that have been reported to cause Stevens-Johnson syndrome include the following:

• Herpes simplex virus (possibly; remains a debated issue)
• AIDS
• Coxsackie viral infections
• Influenza
• Hepatitis
• Mumps

In children, Epstein-Barr virus and enteroviruses have been identified. More than half of the patients with Stevens-Johnson syndrome report a recent upper respiratory tract infection.

Bacterial etiologies include the following:

• Group A beta-hemolytic streptococci
• Diphtheria
• Brucellosis
• Lymphogranuloma venereum
• Mycobacteria
• Mycoplasma pneumoniae^{[11, 12]}
• Rickettsial infections
• Tularemia
• Typhoid

Possible fungal causes include coccidioidomycosis, dermatophytosis, and histoplasmosis. Malaria and trichomoniasis have been reported as protozoal causes.

Drug-induced

Antibiotics are the most common cause of Stevens-Johnson syndrome, followed by analgesics, cough and cold medication, NSAIDs, psychoepileptics, and antigout drugs. Of antibiotics, penicillins and sulfa drugs are prominent; ciprofloxacin has also been reported^[13]

The following anticonvulsants have been implicated:

• Phenytoin
• Carbamazepine
• oxcarbazepine (Trileptal)
• Valproic acid
• Lamotrigine
• Barbiturates

Mockenhapupt et al stressed that most anticonvulsant-induced SJS occurs in the first 60 days of use.^[14]

Antiretroviral drugs implicated in Stevens-Johnson syndrome include nevirapine and possibly other non-nucleoside reverse transcriptase inhibitors.^[15] Indinavir has been mentioned.

Stevens-Johnson syndrome has also been reported in patients taking the following drugs:

• Modafinil (Provigil)
• Allopurinol^[16]
• Mirtazapine^[17]
• TNF-alpha antagonists (eg, infliximab, etanercept, adalimumab)^[18]
• Cocaine

Genetic factors

There is strong evidence for a genetic predisposition to severe cutaneous adverse drug reactions such as Stevens-Johnson syndrome. Carriage of the following human leukocyte antigens has been associated with increased risk:

• HLA-B*1502
• HLA-B*5801
• HLA-B*44
• HLA-A29
• HLA-B12
• HLA-DR7
• HLA-A2
• HLA-B*5801
• HLA-A*0206
• HLA-DQB1*0601

Certain of these HLA alleles are associated with an increased probability of developing Stevens-Johnson syndrome upon exposure to specific drugs. The US Food and Drug Administration (FDA) and Health Canada advise screening for HLA-B*1502 in patients of southeastern Asian ethnicity before starting treatment with carbamazepine. (The risk is much lower in other ethnic populations, making screening impractical in them). HLA-B*5801 confers a risk of allopurinol-related reactions.^[19] Pretreatment screening is not readily available.^[20]

Whites with HLA-B*44 appear to be more susceptible to develop Stevens-Johnson syndrome. HLA-A29, HLA-B12, and HLA-DR7 are frequently associated with sulfonamide-induced Stevens-Johnson syndrome, while HLA-A2 and HLA-B12 are often encountered in Stevens-Johnson syndrome induced by nonsteroidal anti-inflammatory drugs (NSAIDs).

HLA-A*0206 and HLA-DQB1*0601 allele have been shown to be was strongly associated with Stevens-Johnson syndrome with ocular disease.^{[21, 22]}

Nevertheless, whether the presence of those genes constitutes a predisposition to Stevens-Johnson syndrome or whether those genes are in linkage disequilibrium with more relevant adjacent genes is unknown.^[23]

Epidemiology

Strom et al reviewed Medicaid billing data from 1980-1984 in Michigan, Minnesota, and Florida to determine the incidence of Stevens-Johnson syndrome; the incidence rates were 7.1, 2.6, and 6.8 cases per million population per year, respectively.^[24]

Cases tend to have a propensity for the early spring and winter.

For overlapping SJS and TEN, oxicam NSAIDs (piroxicam, meloxicam, tenoxicam) and sulfonamides are most commonly implicated in the United States and other western nations.^[20]

SJS occurs with a worldwide distribution similar in etiology and occurrence to that in the United States. However, a study from Germany reported only 1.1 cases per 1 million person-years.

In contrast to the drugs most often implicated in western nations, allopurinol is the most common offending agent in Southeast Asian nations, including Malaysia, Singapore, Taiwan, and Hong Kong.^[20]

Race-, sex-, and age-related demographics

Stevens-Johnson syndrome has been described worldwide in all races, although it may be more common in whites. Interestingly, disease is not limited to humans; cases have been reported in dogs, cats, and monkeys.

The proportion of females has been estimated to be 33-62%. The largest series reports 39.9% of females in a group of 315 patients with Stevens-Johnson syndrome.

In a large cohort, the mean age of patients with Stevens-Johnson syndrome was 25 years. In a smaller series, the mean age of patients with Stevens-Johnson syndrome was reported as 47 years. However, cases have been reported in children as young as 3 months.

Prognosis

Individual lesions typically should heal within 1-2 weeks, unless secondary infection occurs. Most patients recover without sequelae.

Mortality is determined primarily by the extent of skin sloughing. When body surface area (BSA) sloughing is less than 10%, the mortality rate is approximately 1-5%. However, when more than 30% BSA sloughing is present, the mortality rate is between 25% and 35%, and may be as high as 50%.^{[25, 20]} Bacteremia and sepsis appear to play a major role in increased mortality.^[26]

The SCORTEN score (a severity-of-illness score for toxic epidermal necrolysis) calculates the risk for death in both SJS and TEN on the basis of the following variables:

• Age >40 years
• Malignancy
• Heart rate >120
• Initial percentage of epidermal detachment >10%
• Blood urea nitrogen (BUN) level >10 mmol/L
• Serum glucose level >14 mmol/L
• Bicarbonate level < 20 mmol/L

Each variable is assigned a value of 1 point. Mortality rates are as follows:

• 0-1 points, ≥3.2%
• 2 points, ≥12.1%
• 3 points, ≥35.3%
• 4 points, ≥58.3%
• 5 or more points, ≥90%

Other negative prognostic factors include persistent neutropenia (defined as neutropenia lasting more than 5 days), hypoalbuminemia (usually < 2 g/dL), and persistent azotemia.

Although some patients rapidly progress to lose very large areas of the epidermis in a matter of days, the process suddenly ceases in others and reepithelialization begins a few days later. Predicting the course of disease in a given patient at the initial presentation is not possible. Reepithelialization is usually complete within 3 weeks, but pressure and mucosal areas may remain eroded and crusted for 2 weeks or longer.

Survivors of Stevens-Johnson syndrome may experience numerous long-term sequelae; the most disabling are those of the eye. Cicatrization of conjunctival erosions may lead to the following:

• Inverted eyelashes
• Photophobia
• A burning sensation in the eyes
• Watery eyes
• A siccalike syndrome
• Corneal and conjunctival neovascularization

As many as 40% of survivors of toxic epidermal necrolysis have residual potentially disabling lesions that may cause blindness.

History

Typically, Stevens-Johnson syndrome (SJS) begins with a nonspecific upper respiratory tract infection. This usually is part of a 1- to 14-day prodrome during which fever, sore throat, chills, headache, and malaise may be present. Vomiting and diarrhea are occasionally noted as part of the prodrome.

Mucocutaneous lesions develop abruptly. Clusters of outbreaks last from 2-4 weeks. The lesions are typically nonpruritic.

A history of fever or localized worsening should suggest a superimposed infection; however, fever has been reported to occur in up to 85% of cases.

Involvement of oral and/or mucous membranes may be severe enough that patients may not be able to eat or drink. Patients with genitourinary involvement may complain of dysuria or an inability to void.

A history of a previous outbreak of Stevens-Johnson syndrome or of erythema multiforme may be elicited. Recurrences may occur if the responsible agent is not eliminated or if the patient is reexposed.

Typical prodromal symptoms are as follows:

• Cough productive of a thick purulent sputum
• Headache
• Malaise
• Arthralgia

Patients may complain of a burning rash that begins symmetrically on the face and the upper part of the torso. This may be accompanied by ocular symptoms.

In addition to the skin, lesions in Stevens-Johnson syndrome may involve the following parts of the body:

• Oral mucosa
• Esophagus
• Pharynx
• Larynx
• Anus
• Trachea
• Vagina
• Urethra

Ocular symptoms include the following:

• Red eye
• Tearing
• Dry eye
• Pain
• Blepharospasm
• Itching
• Grittiness
• Heavy eyelid
• Foreign body sensation
• Decreased vision
• Burn sensation
• Photophobia
• Diplopia

Delineation of a drug exposure timeline is essential, especially in the 1-3 weeks preceding the cutaneous eruption.

Physical Examination

The rash can begin as macules that develop into papules, vesicles, bullae, urticarial plaques, or confluent erythema. The center of these lesions may be vesicular, purpuric, or necrotic.

The typical lesion has the appearance of a target; this is considered pathognomonic. However, in contrast to the typical lesions of erythema multiforme, these lesions have only two zones of color. The core may be vesicular, purpuric, or necrotic; that zone is surrounded by macular erythema. Some have called these targetoid lesions.

Lesions may become bullous and later rupture, leaving denuded skin. The skin becomes susceptible to secondary infection. Extensive sloughing is shown in the image below.

Note extensive sloughing of epidermis from Stevens-Johnson syndrome. Courtesy of David F. Butler, MD.

Urticarial lesions typically are not pruritic. Infection may be responsible for the scarring associated with morbidity.

Although lesions may occur anywhere, the palms, soles, dorsum of the hands, and extensor surfaces are most commonly affected. Desquamation on the foot is shown in the image below.

Sheetlike desquamation on the foot in a patient with toxic epidermal necrolysis. Courtesy of Robert Schwartz, MD.

The rash may be confined to any one area of the body, most often the trunk.

Mucosal involvement may include erythema, edema, sloughing, blistering, ulceration, and necrosis. An example of this type of involvement is shown in the image below.

Hemorrhagic crusting of the mucous membranes in toxic epidermal necrolysis. Similar lesions are seen in Stevens-Johnson syndrome. Courtesy of Robert Schwartz, MD.

For more information, see the Medscape Reference article Dermatologic Manifestations of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis.

Although some have suggested the possibility of Stevens-Johnson syndrome without skin lesions, most believe that mucosal lesions alone are not enough to establish the diagnosis. Cases without skin lesions have been termed "atypical" or "incomplete."^[11] These authors suggested that the combination of urethritis, conjunctivitis, and stomatitis established the diagnosis of Stevens-Johnson syndrome in a patient with Mycoplasma pneumonia– induced signs and symptoms.

The following signs may be noted on examination:

• Fever
• Orthostasis
• Tachycardia
• Hypotension
• Altered level of consciousness
• Epistaxis
• Conjunctivitis
• Corneal ulcerations
• Erosive vulvovaginitis or balanitis
• Seizures
• Coma

The following signs may be noted on external examination:

• Conjunctival hyperemia (ie, red eye)
• Entropion
• Skin lesions
• Nasal lesions
• Mouth lesions
• Discharge (ie, catarrhal, mucous, membranous)

The following ocular signs may be noted on slit lamp examination (see the images below):

• Eyelids: Trichiasis, distichiasis, meibomian gland dysfunction, blepharitis
• Conjunctiva: Papillae, follicles, keratinization, subepithelial fibrosis, conjunctival shrinkage, foreshortening of fornices, symblepharon, ankyloblepharon
• Cornea: Superficial punctate keratitis, epithelial defect, stromal ulcer, neovascularization, keratinization, limbitis, conjunctivalization, stromal opacity, perforation A patient with severe eye involvement associated with Stevens-Johnson syndrome. Note corneal neovascularization and conjunctivalization of the ocular surface. Epithelial defect of the cornea with neovascularization and surface conjunctivalization.

Complications

Of patients with Stevens-Johnson syndrome, 27-50% progress to severe ocular disease. Ocular complications of Stevens-Johnson syndrome include the following:

• Chronic cicatrizing conjunctivitis
• Corneal epithelial defects
• Corneal stromal ulcers
• Corneal perforation
• Endophthalmitis

Other complications may include the following:

• Gastroenterologic - Esophageal strictures
• Genitourinary - Renal tubular necrosis, renal failure, penile scarring, vaginal stenosis
• Pulmonary - Tracheobronchial shedding with resultant respiratory failure
• Cutaneous - Scarring and cosmetic deformity, recurrences of infection through slow-healing ulcerations

Lesions may continue to erupt in crops for as long as 2-3 weeks. Mucosal pseudomembrane formation may lead to mucosal scarring and loss of function of the involved organ system. Esophageal strictures may occur when extensive involvement of the esophagus exists. Mucosal shedding in the tracheobronchial tree may lead to respiratory failure.

Blindness may develop secondary to severe keratitis or panophthalmitis in 3-10% of patients. Vaginal stenosis and penile scarring have been reported. Renal complications are rare.

Cutaneous lesions may resolve with a patchwork of hyperpigmentation and hypopigmentation. Fingernails and toenails may regrow abnormally. Lesions of the genitourinary system may lead to phimosis or vaginal synechiae.

Diagnostic Considerations

The gravity of the diagnosis must be recognized. Because patients with Stevens-Johnson syndrome (SJS) who present early in the development of the disease may not yet be critically ill, the clinician may misdiagnose the condition and discharge the patient. SJS should be considered in all patients with target lesions and mucous membrane involvement.

Other problems to be considered in the differential diagnosis include the following:

• Staphylococcal scalded skin syndrome
• Irradiation
• Trauma
• Progressive systemic sclerosis (scleroderma)
• Erythroderma ichthyosiform congenita
• Porphyria cutanea tarda
• Epidermolysis bullosa acquisita
• Linear immunoglobulin A bullous disease
• Paraneoplastic pemphigus
• Bullous systemic lupus erythematosus
• Corynebacterium diphtheriae conjunctivitis
• Sebaceous cell carcinoma
• Adenoviral conjunctivitis
• Intraepithelial epithelioma
• Acute generalized exanthematic pustulosis

Differential Diagnoses

• Chemical Burns in Emergency Medicine
• Exfoliative Dermatitis
• Keratoconjunctivitis, Atopic
• Ocular Burns
• Sjogren Syndrome
• Thermal Burns in Emergency Medicine
• Toxic Shock Syndrome
• Trachoma

Approach Considerations

There are no specific laboratory studies (other than biopsy) that can definitively establish the diagnosis of Stevens-Johnson syndrome.

Serum levels of the following are typically elevated in patients with Stevens-Johnson syndrome:

• Tumor necrosis factor (TNF)-alpha
• Soluble interleukin 2-receptor
• Interleukin 6
• C-reactive protein

However, none of these serologic tests is used routinely in diagnosing and managing Stevens-Johnson syndrome.

A complete blood count (CBC) may reveal a normal white blood cell (WBC) count or a nonspecific leukocytosis. A severely elevated WBC count indicates the possibility of a superimposed bacterial infection. Electrolytes and other chemistries may be needed to help manage related problems.

Skin and blood cultures have been advocated because the incidence of serious bacterial bloodstream infections and sepsis contribute to morbidity and mortality.^[26] In addition, cultures of urine and wounds are indicated when an infection is clinically suspected. Determine renal function and evaluate urine for blood.

Skin biopsy specimens demonstrate that the bullae are subepidermal. However, skin biopsy is not an emergency department (ED) procedure. Epidermal cell necrosis may be noted. Perivascular areas are infiltrated with lymphocytes.

Bronchoscopy, esophagogastroduodenoscopy (EGD), and colonoscopy may be indicated. Chest radiography may indicate the existence of a pneumonitis when clinically suspected. Otherwise, routine plain films are not indicated.

Histologic Findings

Minimal dermal inflammatory cell infiltrate and full-thickness necrosis of epidermis are typical histopathologic findings in patients with Stevens-Johnson syndrome. The epidermal-dermal junction shows changes, ranging from vacuolar alteration to subepidermal blisters. The dermal infiltrate is superficial and mostly perivascular. Keratinocytes undergo apoptosis.

In the dermis, CD4⁺ T lymphocytes predominate, whereas in the epidermis, the T cells are predominantly CD8⁺. The dermoepidermal junction and epidermis is infiltrated mostly by CD8⁺ T lymphocytes. Complement 3 component and immunoglobulin G (IgG) deposits at the dermoepidermal junction and around small dermal vessels were interpreted as the result of a nonspecific exudative phenomenon. The activated state is underlined by human leukocyte antigen (HLA)-DR expression on keratinocytes, similar to other skin inflammatory disorders.

CD8⁺ T cells that recognize major histocompatibility complex I (MHC-I) modified by an antigen may produce skin lesions of Stevens-Johnson syndrome, or they may be produced by T cells that recognize an antigen that is restricted by MHC-I.

Conjunctival biopsies from patients with active ocular disease show subepithelial plasma cells and lymphocyte infiltration. Lymphocytes also are present around vessel walls. The predominant infiltrating lymphocyte is the helper T cell.

Immunohistology of the conjunctiva reveals numerous HLA-DR–positive cells in the substantia propria, vessel walls, and epithelium. In the epithelium, HLA-DR is presented by Langerhans cells, macrophages, and activated T cells.

Immunoreactant deposition in vessel walls, comprised of immunoglobulin and complement components, is another prominent feature.

On transmission electron microscopy, the conjunctivae of patients with episodic conjunctival inflammation revealed squamous epithelial metaplasia, vascular basement membrane zone disruption, reduplication, and thickening.

In vivo confocal microscopy may be a useful tool for therapeutic indications and follow-up of ocular problems associated with Stevens-Johnson syndrome.^[27]

Approach Considerations

Management of patients with Stevens-Johnson syndrome is usually provided in intensive care units or burn centers. No specific treatment of Stevens-Johnson syndrome is noted; therefore, most patients are treated symptomatically. In principle, the symptomatic treatment of patients with Stevens-Johnson syndrome does not differ from the treatment of patients with extensive burns.

Prehospital and emergency department care

Paramedics should recognize the presence of severe fluid loss and should treat patients with Stevens-Johnson syndrome as they would patients with thermal burns.

Most patients present early and prior to obvious signs of hemodynamic compromise. The single most important role for the ED physician is to detect Stevens-Johnson syndrome/toxic epidermal necrolysis early and initiate the appropriate ED and inpatient management.

Withdrawal of the suspected offending agent is critically important. Timing of withdrawal has been linked to outcome. Underlying diseases and secondary infections must be identified and treated.

Patients should be treated with special attention to airway and hemodynamic stability, fluid status, wound/burn care, and pain control. Care in the ED must be directed to fluid replacement and electrolyte correction. Treatment is primarily supportive and symptomatic. Some have advocated corticosteroids, cyclophosphamide, plasmapheresis, hemodialysis, and immunoglobulin.

Manage oral lesions with mouthwashes. Topical anesthetics are useful in reducing pain and allowing the patient to take in fluids.

Skin lesions are treated as burns. Areas of denuded skin must be covered with compresses of saline or Burow solution.

Address tetanus prophylaxis.

Supportive Systemic Therapy

Fluid management is provided by macromolecules and saline solutions during the first 24 hours. Phosphate salts are necessary in the presence of hypophosphatemia. The amount of fluids required in patients with Stevens-Johnson syndrome is usually less than in those patients with burns covering the same body surface area.

After the second day of hospitalization, oral intake of fluids provided by nasogastric tube is often begun, so that intravenous fluids can be tapered progressively and discontinued, usually in 2 weeks.

Massive parenteral nutrition is necessary as soon as possible to replace the protein loss and to promote healing of cutaneous lesions. Intravenous insulin therapy may be required because of impaired glycoregulation.

Environmental temperature raised to 30-32°C reduces caloric loss through the skin. Fluidized air beds are recommended if a large portion of the skin on the patient's backside is involved. Heat shields and infrared lamps are used to help reduce heat loss.

Anticoagulation with heparin for the duration of hospitalization is recommended. Antacids reduce the incidence of gastric bleeding.

Pulmonary care includes aerosols, bronchial aspiration, and physical therapy. Tranquilizers are used to the extent limited by respiratory status.

Infection Control

Patients with Stevens-Johnson syndrome are at a high risk of infection. Sterile handling and/or reverse-isolation nursing techniques are essential to decrease the risk of nosocomial infection. Cultures of blood, catheters, gastric tubes, and urinary tubes must be performed regularly.

Because of the association between Stevens-Johnson syndrome and sulfonamides, avoid the use of silver sulfadiazine, which is commonly used in burn units. Instead, use another antiseptic, such as 0.5% silver nitrate or 0.05% chlorhexidine, to paint and bathe the affected skin areas.

Prophylactic systemic antibiotics are not recommended. Antimicrobials are indicated in cases of urinary tract or cutaneous infections, either of which may lead to bacteremia.

The diagnosis of sepsis is difficult. Carefully consider the decision to administer systemic antibiotics. The first signs of infection are an increase in the number of bacteria cultured from the skin, a sudden drop in fever, and deterioration of the patient's condition, indicating the need for antibiotic therapy.

The choice of antibiotic is usually based on the bacteria present on the skin. Because of impaired pharmacokinetics, similar to that present in burn patients, the administration of high doses may be required to reach therapeutic levels. Monitoring the serum levels is necessary to adjust the dosage.

Skin Care

Several skin care approaches have been described. Extensive debridement of nonviable epidermis, followed by immediate cover with biologic dressings, are among the recommended treatments. Biologic dressings may include the following:

• Porcine cutaneous xenografts
• Cryopreserved cutaneous allografts
• Amnion-based skin substitutes
• Collagen-based skin substitutes

The ophthalmology literature supports concurrent coverage of the involved eye(s) with amniotic membrane.^[28]

Leaving the involved epidermis that has not yet peeled off in place and using biologic dressings only on raw dermis also has been recommended. Skin allotransplantation reduces pain, minimizes fluid loss, improves heat control, and prevents bacterial infection. Hyperbaric oxygen can also improve healing.

Immunomodulatory Therapy

Stevens-Johnson syndrome is a rare disorder with relatively high mortality and morbidity rates. To date, because of a lack of consensus on the proposed therapeutic modalities, intensive supportive management and withdrawal of the offending drug remain the criterion standard.

For any intervention, a prospective randomized controlled trial would be the most appropriate step to validate its use. However, a large number of patients are required to reach statistical significance. Furthermore, for ethical reasons, withdrawal of a potentially life-saving therapy for the sake of randomization with a placebo control is not possible.

Several therapeutic modalities have been advocated for the treatment of Stevens-Johnson syndrome based on the current, yet incomplete, understanding of its pathogenetic mechanisms. Plasmapheresis, immunosuppressive therapy, and intravenous immunoglobulin (IVIG) have been used with variably successful results.

The use of systemic steroids remains controversial. Some authors believe that they are contraindicated, especially because there may be some question about the diagnosis. Patients with infection-induced erythema multiforme do worse when steroids are given. (Note that the differentiation between Stevens-Johnson syndrome and erythema multiforme should be possible even in the acute stage.)^[29] Prolonged treatment with systemic steroids has been associated with an increased prevalence of complications.

However, concerns about the safety of systemic corticosteroids in the treatment of Stevens-Johnson syndrome are based on a few case series; in those reports, systemic corticosteroids were administered too late in the course of the disease, in inappropriately low doses, and for a very long duration that actually impaired the healing process and increased the risk of sepsis. The currently advocated approach for corticosteroid use suggests the early use of short-term (4-7 days), high-dose intravenous corticosteroids.^{[30, 31]}

The ophthalmology literature contains several papers that advocate systemic and topical steroids to minimize ocular morbidity.^{[32, 33]} Authors have cited salvage of vision when pulse steroid therapy has been given.^{[29, 33]} Others have concluded that IV steroids and immunoglobulins do not improve outcome.^[34]

The role of other immunosuppressive therapy, that is, cyclosporine, azathioprine, or cyclophosphamide, in the acute phase is less popular, particularly since such medication typically takes weeks to begin to influence immunological reactions. Cyclophosphamide has been reported to be the culprit drug that induced Stevens-Johnson syndrome in one instance.^[35]

Nevertheless, the role of cyclosporine in the treatment of the acute phase of Stevens-Johnson syndrome has been revisited, and, indeed, it showed encouraging results.^[8] Also, immunosuppressive therapy may play a pivotal role in the management of the chronic ocular surface inflammation that can occur later on in selected cases.

The rationale for the use of IVIG is the most appealing. Based on in vitro and clinical data, IVIG can block the Fas receptors on the surface of the keratinocytes, thus interfering with the Fas-Fas ligand mediated apoptosis.^[36] Encouraging results were reported when IVIG was used in high doses very early in the course of the disease and for a short period. Unfortunately, there is no consensus with regard to either the dose or the duration of treatment with IVIG.^[4]

Prophylactic use of IVIG has also been reported. One group used IVIG in a patient who underwent cardiac catheterization but who had 4 previous Stevens-Johnson syndrome episodes after intravenous contrast injection.^[37]

However, a large European study designed to evaluate the efficacy of various treatments, the EuroSCAR Study, "found no sufficient evidence of a benefit for any specific treatment."^[38] The group looked at mortality in patients treated with IVIG and corticosteroids. However, in a letter to the editor, Pehr disagreed with the findings in the EuroSCAR study citing inadequate doses of IVIG and corticosteroids in that study.^[39]

Interestingly, few studies have addressed the effect of systemic steroids or IVIG on either the development or the outcome of ocular manifestations in Stevens-Johnson syndrome and toxic epidermal necrolysis (TEN). Neither treatment appeared to have an effect on the ocular outcome in patients in two reports.^{[40, 1]}

Treatment of Acute Ocular Manifestations

Treatment of acute ocular manifestations usually begins with aggressive lubrication of the ocular surface. As inflammation and cicatricial changes ensue, most ophthalmologists use topical steroids, antibiotics, and symblepharon lysis.

In case of exposure keratopathy, tarsorrhaphy may be required.

Maintenance of ocular integrity can be achieved through the use of amniotic membrane grafting, adhesive glues, lamellar grafts, and penetrating keratoplasty, either in the acute phase or in subsequent follow-up care.

Visual rehabilitation in patients with visual impairment can be considered once the eye has been quiet for at least 3 months.

Treatment of Chronic Ocular Manifestations

In the case of mild chronic superficial keratopathy, long-term lubrication may be sufficient. In addition to lubrication, some patients may require a cosmetically acceptable long-term lateral tarsorrhaphy.

The visual rehabilitation in patients with severe ocular involvement, resulting in profound dry eye syndrome with posterior lid margin keratinization, limbal stem cell deficiency, persistent epithelial defects with subsequent corneal neovascularization, and frank corneal opacity with surface conjunctivalization and keratinization, is difficult and often frustrating for both the patient and the physician. A close, usually long-term, relationship between the patient and the ophthalmologist needs to be established to achieve the best possible result.

The removal of keratinized plaques from the posterior lid margins, along with mucous membrane grafting and/or amniotic membrane grafting, is usually the first step and one of the most important determining factors in the future success of corneal surgeries. Preferably, a skilled oculoplastic surgeon with specific experience on patients with Stevens-Johnson syndrome should perform this procedure.

Subsequently, limbal stem cell transplantation and amniotic membrane grafting with superficial keratectomy removing conjunctivalized or keratinized ocular surface can follow. Patients with persistent corneal opacity require lamellar or penetrating keratoplasty in the next step, but each exposure to alloantigenic material increases the odds of tissue rejection. Therefore, the author’s advice is to strive for major, if not perfect, resurrection of the useful vision, rather than perform allografts of both eyes and keratoplasties.

To preserve corneal clarity after the visual reconstruction, the long-term use of gas-permeable scleral contact lenses may be necessary to protect the ocular surface. Long-term management frequently involves the treatment of trichitic lashes and/or eyelid margin repair for distichiasis or entropion. If the ocular surface repeatedly fails to heal after multiple surgical interventions, keratoprosthesis may be considered as a last resort.

Consultations and Long-Term Monitoring

Consultants may help establish the diagnosis and direct inpatient care. A dermatologist is the most likely clinician to establish the diagnosis, with or without biopsy. Severe cases may require the involvement of a burn specialist or plastic surgery specialist. Internal medicine, critical care, or pediatrics consultants direct inpatient care. Ophthalmology consultation is mandatory for those with ocular involvement. Depending on organ system involvement, consultations with a gastroenterologist, pulmonologist, and nephrologist may be helpful.

Patients with SJS require regular monitoring of their medications and status. Although patients with erythema multiforme minor may be treated as outpatients with topical steroids, those with erythema multiforme major (ie, Stevens-Johnson syndrome) must be hospitalized. Cases of erythema multiforme minor must be followed closely. Some authors recommend daily follow-up.

Medication Summary

The goal of pharmacotherapy in patients with Stevens-Johnson syndrome (SJS) is to reduce morbidity and to prevent complications. No specific drug treatment has been consistently shown to be beneficial in the treatment of SJS. The choice of antibiotic for infectious causes depends on the cause of that infection.

Clinical and laboratory evidence suggesting bloodstream infection mandates the use of antibiotics. The most common organisms include Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae species.^[26]

The use of systemic corticosteroids is controversial, but may be useful in high doses early in the disease. Morbidity and mortality actually may increase in association with corticosteroid use. For persistent or recurrent ocular inflammation, patients may benefit from short-term systemic corticosteroids and/or long-term immunosuppressive therapy, which may reduce severity of conjunctivitis and improve prognosis quod visum by reducing damage to ocular surface.

Human intravenous immunoglobulin (IVIG) has been described as both treatment and prophylaxis.

Corticosteroids

Class Summary

These agents have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli.

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Prednisone

Prednisone is an immunosuppressant for treatment of autoimmune disorders. It may decrease inflammation by reversing increased capillary permeability and suppressing polymorphonuclear neutrophil (PMN) activity.

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Methylprednisolone (Solu-Medrol, Medrol, Depo-Medrol)

Methylprednisolone decreases inflammation by suppressing migration of PMNs and reversing increased capillary permeability.

Immunosuppressants

Class Summary

These agents inhibit key factors of the immune system, reducing overall immune activity.

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Cyclosporine (Sandimmune, Neoral)

Cyclosporine is a cyclic polypeptide that suppresses some humoral immunity and, to a greater extent, cell-mediated immune reactions such as delayed hypersensitivity, allograft rejection, experimental allergic encephalomyelitis, and graft-vs-host disease for a variety of organs.

For children and adults, base dosing on ideal body weight.

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Cyclophosphamide (Cytoxan, Neosar, Gengraf)

Cyclophosphamide is chemically related to nitrogen mustards. As an alkylating agent, the mechanism of action of the active metabolites may involve cross-linking of DNA, which may interfere with the growth of immune cells.

Immune Globulins

Class Summary

These agents are used to improve clinical and immunologic aspects of the disease. They may decrease autoantibody production, and they may increase solubilization and removal of immune complexes.

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Immune globulin intravenous (Gammaplex, Hizentra, Octagam, Privigen, Gammagard S/D)

IVIG neutralizes circulating myelin antibodies through anti-idiotypic antibodies; down-regulates proinflammatory cytokines, including interferon-gamma; blocks Fc receptors on macrophages; suppresses inducer T and B cells and augments suppressor T cells; blocks complement cascade; and promotes remyelination. IVIG may increase IgG levels (by 10%) in the cerebrospinal fluid.