Page 38/54 · Shock Syndromes II

Data Tables

Shock Syndromes II

Mahmoud A. Ammar ~3 min read Module 16 of 20

/ 54

Shock Syndromes II

III.STEVENS-JOHNSON SYNDROME AND TOXIC EPIDERMAL NECROLYSIS

A.Epidemiology

Severe cutaneous reactions and related syndromes are unpredictable and rare. The primary causes

of these injuries include drugs, dysregulated immune response, and acute infection. Stevens-Johnson

syndrome (SJS), toxic epidermal necrolysis (TEN; also called Lyell syndrome), and drug hypersensitivity

syndrome, or DRESS (drug rash with eosinophilia and systemic symptoms), are the most common

presentations. There is a suggestion of genetic influence on the occurrence of SJS and TEN.

2SJS and TEN are the most severe of reactions, representing different points on a similar spectrum of

cutaneous injury involving epidermolysis or separation of the epidermis from the dermis.

Similar to thermal injury, the TBSA affected is used to describe the extent of cutaneous injury. According

to contemporary reports from US burn centers, the mean TBSA involvement for patients with TEN is

greater than 60%.

The incidence of severe cutaneous reactions is difficult to estimate. The highest rates reported approach

20%; however, definitions include mild to moderate reactions. The incidence of SJS and TEN is relatively

low. SJS and TEN are considered rare diseases, with SJS occurring at a rate of about 1 to 2 cases per

million people per year and TEN even less commonly, at about 0.4 to 1.2 cases per million people per

year. Patients with HIV infection may have a higher incidence.

Severity of clinical presentation is associated with the extent of tissue and mucosal injury and necrosis.

Most patients have a prodromal fever and malaise preceding cutaneous symptoms. Clinical presentation

usually includes fever, systemic inflammatory response syndrome, hypotension from cytokine-mediated

vasodilation, and mild to moderate hypovolemia from volume depletion and third spacing. Bleeding may

also be present, depending on the extent of mucosal injury.

Health care–associated or nosocomial complications, including pneumonia, catheter-associated UTIs,

central line–associated bloodstream infections, and malnutrition, are common in severely injured

patients.

SJS and TEN are life-threatening reactions. Average crude mortality associated with SJS/TEN is 25%

to 55% and can be as high as 90%.

B.Definitions

SJS and TEN are part of the same disease process, differing in severity. Common features of SJS and

TEN include cutaneous erythema, progressive blistering, epidermolysis, and mucosal erosions.

2The most widely accepted classification system for SJS and TEN was proposed in 1993. This system

includes 5 categories: