While researching for the cause of my son's allergy problem I found a condition called Hyper-IgE that can cause boils with MRSA, have your doctor check out Hyper-IgE. There are several web sites that list all the symptoms.
Effective, on-going drainage of the boil will be as important as the antibiotic therapy. First, you should re-confirm that the Staph causing your daughter’s infection, truly is one of the more resistant, more dangerous varieties. For a very long time, a medicine called vancomycin has been the treatment of choice for infection with Methicillin-resistant staphylococcus aureus (MRSA). Now, other medicines seem to be more effective, including teicoplanin and linezolid. You might want to discuss this with her doctors and ask if consultation with an infectious disease specialist might be appropriate, given that this may be a recurrent Staph infection. Also, you and other family members should be checked to be sure that none of you or any other person regularly in close contact with your daughter is a Staph nasal carrier of the bacteria.