Panton-Valentine leukocidin is associated with exacerbated skin manifestations and inflammatory response in children with community-associated staphylococcal scarlet fever.

BACKGROUND Staphylococcal scarlet fever (SSF), a rare disease, was first described in 1900. The clinical features and outcomes in children with SSF caused by Panton-Valentine leukocidin (PVL)-positive and PVL-negative Staphylococcus aureus strains have not been compared prospectively. METHODS The demographic data, selected clinical features, laboratory values, and outcomes for 49 consecutive children with community-acquired S. aureus SSF prospectively identified during an 11-year period were collected for analysis. RESULTS The male-to-female ratio was 1.88, and the median age of the patients was 37 months. Cutaneous abscesses predominated among children with SSF. Methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) caused SSF in 26 and 23 children, respectively. Twenty-four isolates had results that were positive for PVL (5 MSSA and 19 MRSA isolates), and 25 had results that were negative for PVL (21 MSSA and 4 MRSA isolates). Polymerase chain reaction revealed that most (92%) contained only staphylococcal enterotoxin B (23 MSSA and 22 MRSA isolates). By multivariate analysis, children with PVL-positive isolates had significantly larger abscess sizes, higher white blood cell counts, higher C-reactive protein levels, and longer durations of fever, generalized scarlatiniform rashes, and hospital stays. Most (17 isolates; 89%) of the 19 PVL-positive MRSA isolates carried the staphylococcal cassette chromosome mec V(T) and all were multilocus sequence type 59. CONCLUSION SSF caused by PVL-positive S. aureus strains were associated with more-exacerbated skin manifestations and a greater systemic inflammatory response, compared with those cases caused by PVL-negative S. aureus. Clinical improvement after incision and drainage was achieved for most children with SSF caused by PVL-positive MRSA strains, despite treatment with an ineffective antibiotic.