How do you get cellulitis?

Mostly people get cellulitis infection of dermis and subcutaneous tissues after minor skin trauma such as insect bites, cuts and burns. On this spot where skin was previously broken bacteria enters into human body causing this type of infection.

I have this from a shot at the doctor's, too. It's shown by a spot of swollen, red, usually itchy and/or painful skin around a bite or break in the skin.