If you are certain that he has impetigo (that is, if a doctor has confirmed it), then I hope that you have been carefully instructed about how to care for the affected areas.
Impetigo is highly contagious. You should wear gloves (disposable, just lightweight plastic) when applying the medication. Since his impetigo is now on multiple locations he may need an oral antibiotic. Simply putting a drugstore antibiotic cream on it may not be enough. Even if he doesn't need an oral antibiotic, he may need a prescription cream.
And yes, often impetigo can be loosely bandaged, mostly to prevent touching it, or to prevent the spread of the contagion. Impetigo can develop into other things - my daughter had impetiginous eczema which then also turned into a serious staph infection (a different one than the impetigo). So don't underestimate impetigo.
Bottom line: make sure you're getting proper medical care for this highly contagious infection, disinfecting things that he touches, laundering sheets and towels and clothing in hot water, using gloves to prevent spreading the infection to yourself and others, and while the infection is in its worst stages, keeping him away from other babies.