Skin Findings of Staphylococcus aureus Toxin-mediated Infection in Relation to Toxin Encoding Genes

Background: Staphylococcal scalded skin syndrome and toxic shock syndrome are associated with exfoliatins and superantigens, respectively; and are easy to distinguish in their usual presentation. However, there is confusion about the mild forms of these 2 staphylococcal diseases. These mild forms are both designated as "staphylococcal scarlet fever" despite differences in their pathophysiology and clinical presentation. Our study aimed to distinguish between the clinical characteristics of the rash associated with exfoliatins and the rash associated with superantigens. Methods: Patients were selected from the French National Reference Center for Staphylococci. We retrospectively compared the clinical characteristics of patients with a generalized rash during Staphylococcus aureus infection. Patients who met the criteria of staphylococcal scalded skin syndrome or toxic shock syndrome were excluded. The patients were classified into 2 groups depending on the presence of a gene coding for exfoliatin or for superantigenic toxin. Results: We included 13 cases with exfoliatin and 9 with superantigens. The patients of the exfoliatin group were more likely to have facial involvement, fold involvement and a superficial focus of infection. In the second group, S. aureus was isolated from a deeper focus in 8 of 9 patients. Conclusion: Mild forms of S. aureus toxin-mediated infection affect the pediatric population. Examination made it possible to distinguish an exanthema associated with an exfoliatin from one associated with a superantigen. This early clinical distinction results in differences in management.