Hello, MRSA may cause damage to many organs but the clinical picture of your son probably relates to a viral infection. MRSA can cause sinusitis which usually presents with headaches, nasal congestion and perhaps even fever. I could not tell by your description. Nobody could tell you actually. Cultures are needed to diagnose infections by specific pathogens. Normally in cases like that, doctors do not ask for cultures. I could not also comment on your wound. This description is too vague to be assessed. It could be better assessed in a clinical encounter. If you could provide a good quality picture, it would probably help. In general, MRSA is not a common pathogen in normal individuals. Risk factors for having MRSA include MRSA carriers (MRSA can reside in their noses), hemodialysis or peritoneal dialysis patients, diabetes, cancer, hospitalization, stroke etc. Of course close contacts can acquire MRSA from high risk patients. So the answer is that unless you have any of the above you re not likely to have MRSA. I hope I ve addressed your concerns! If you need further explanations, please let me know. Kind Regards!