Staphylococcal scalded skin syndrome: potentiation by immunosuppression in mice; toxin-mediated exfoliation in a healthy adult.

Staphylococcal scalded skin syndrome, associated with exfoliative toxin produced by phage group II Staphylococcus aureus, has recently been reported in an adult receiving immunosuppressive therapy. To determine the effect of immunosuppression on the development of the staphylococcal scalded skin syndrome, experimental animals were treated with prednisolone, azathioprine, or a combination of both drugs utilizing the clinical isolate from the adult with scalded skin syndrome. The mean lethal dose and mean exfoliating dose were identical and were 6,000-fold lower in animals receiving both drugs or azathioprine alone. The isolate was not more virulent and did not produce more toxin than other group II phage-type strains. Furthermore, immunosuppressive therapy failed to enhance the susceptibility of experimental animals to a purified preparation of toxin. Finally, purified exfoliative toxin was demonstrated to produce erythema, Nikolsky's sign, bullous formation, and flaking desquamation in a normal human adult. The results demonstrated the enhanced susceptibility of experimental animals receiving immunosuppressive therapy to the development of the staphylococcal scalded skin syndrome. They further showed that human adults are susceptible to the action of exfoliative toxin and suggested that, in the host with compromised defense mechanisms, toxin-producing strains may invade and initiate infection resulting in toxin production and exfoliation.