Exfoliatins

Highly specific, heat-stable proteins (exotoxins), with a molecular weight of 26 to 32 kD, produced by various Staphylococcus aureus species (mainly phage type II), which can cause intraepidermal blistering of the skin in humans.

Several exfoliatins are distinguished. Exfoliatin A (ETA) and exfoliatin B (ETB, identical with D). Their toxic effects are identical. They act as glutamate-specific serine proteases that cleave the cadherin "desmoglein 1" with a high molecular specificity. Desmoglein 1 is an adhesive protein in the desmosomes of the stratum granulosum. Its destruction leads (as in pemphigus foliaceus) to a high-level intraepidermal cleavage (between stratum spinosum and stratum granulosum). The mucous membranes do not blister because they do not form desmoglein 1 and thus the substrate for the exfoliatins is missing!

Circulating exfoliatins are responsible for the clinical appearance of Staphylococcal scalded skin syndrome (SSSS). They are also responsible for staphylogenic scarlet fever. Furthermore, exfoliatins cause the formation of blisters in (staphylococcus induced) large blistered impetigo contagiosa.

Other staphylococcal toxins such as toxic shock syndrome toxin 1 (TSST-1) are responsible for the clinical features of toxic shock syndrome (so-called tampon disease); they also appear to play a pathogenetic role in the erythema scarlatiniforme desquamativum recidivans.

1. Bukowski M et al (2010) Exfoliative toxins of Staphylococcus aureus.toxins (Basel)2:1148-1165

2. Koosha RZ et al (2014) Prevalence of exfoliative toxinA and B genes in Staphylococcus aureus isolated from clinical specimens. J Infect Public Health 7:177-185

3. Role CE et al (2013) Keratinocytes produce IL-6 in response to desmoglein1 cleavage by Staphylococcus aureus exfoliative toxin A. Immunol Res 57:258-267