Scratched open mosquito bites. could this cause an infection? how can i treat this?

Topical Antibiotics: Any opening in the skin can get superinfected with bacteria. The most common is "community acquired staphylococcus" thatcellulitis on occassion is resistant to the usual antibiotic. If you note increasing redness and or pain , especially finger like projections leading away from the redness than this may be cellulitis. Topical and or systemic(oral) antbiotics may be needed.