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.