Staphylococcal scalded skin syndrome. Clinical features, pathogenesis, and recent microbiological and biochemical developments

Abstract

The essential clinical features of staphylococcal scalded skin syndrome (SSSS) and otherforms of toxic epidermal necrolysis (TEN) are contrasted. Whereas TEN is a devastating disease of multiple causes and of high fatality affecting all age groups, SSSS comprises many clinical entitles that occur primarily in early childhood and is caused by certain phage group 2 staphylococci. Because of the high cleavage plane, the barrier is only translently perturbed, and rapid recovery is the rule. Although the early stages of SSSS may resemble other widespread dermatoses clinically, the correct diagnosis is suggested, even prior to frank exfoliation, by the presence of cutaneous tenderness and a positive Nikolski sign. However, rapid bedside confirmation is now possible with exfoliative cytology and frozen sections. Recent availability of in vivo and in vitro animal models of SSSS have advanced the knowledge of the disease: the responsible epidermolytic toxin has been characterized, and the purely extracellular pathogenesis of SSSS has been established. The epidermolytic toxin is strikingly species and tissue specific, attacking only certain keratinizing epithelia of mice, hamsters, monkeys, and man. The lower incidence of SSSS in adults is primarily due to a supreior capacity to metabolize and excrete the toxin, as well as more efficient immune capabilities. The mechanisms of epidermolytic toxin action and the molecular site of action are still the focus of active investigation.

Staphylococcal scalded skin syndrome

“…'l However, addition of protease inhibitors to both in-vitro and in-vivo models of epidermolysis failed to inhibit epidermal splitting". [53][54][55] and, until the demonstration of similarities between ET and serine protease (see below), it was agreed generally that ET had no proteolytic activity.…”

Identification of theStaphylococcus aureus etdPathogenicity Island Which Encodes a Novel Exfoliative Toxin, ETD, and EDIN-B

“…Serologically, ETs involved in human diseases mainly consist of two types, ETA and ETB (6,27). Both toxins cause intraepidermal cleavage through the granular layer, without epidermal necrolysis or an inflammatory response of the skin (6,19,27). Several lines of evidence have suggested that ETs act as serine proteases to induce intraepidermal cleavage: (i) amino acid sequences of ETA and ETB show similarity with the S. aureus V8 serine protease (17), and the catalytic site of V8 protease is conserved in ETA (7); (ii) partially purified ETs preincubated with serine protease inhibitors exhibit delayed skin exfoliation (17); (iii) replacement of the serine residue with glycine in the putative catalytic site of ETA completely abolishes the exfoliative activity of the toxin (35,38); and (iv) crystal structures of ETA (13,53) and ETB (52) have recently been determined, and both types were shown to structurally belong to the chymotrypsin family of serine proteases.…”

Cloning and Sequence Analysis of Genes Encoding Staphylococcus hyicu s Exfoliative Toxin Types A, B, C, and D

“…The complex of skin lesions called the staphylococcal scalded skin syndrome in humans (7,10,16) has several aspects in common with exudative epidermitis in pigs. Staphylococcal scalded skin syndrome is caused by infection with Staphylococcus aureus strains that produce exfoliative toxin ETA, ETB, or both (14).…”