Purulent skin infections are often caused by Staphylococcus aureus including MRSA.
Purulent skin infections are commonly caused by Staphylococcus aureus in contrast to non-purulent infections that may be more likely to be caused by Group A Streptococcus. Coverage should include community acquired MRSA. Prefered parenteral options in younger children include Vancomycin and Clindamycin (depending on local susceptibility patterns). Linezolid and TMP/SMX are alternatives with less clinical data to support their use.
References:
Stevens DL, Bisno AL, Chambers HF, Dellinger EP, Goldstein EJ, Gorbach SL, Hirschmann JV, Kaplan SL, Montoya JG, Wade JC; Infectious Diseases Society of America. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis. 2014 Jul 15;59(2):e10-52. PMID: 24973422