Two types of impetigo have been identified: Nonbullous impetigo. This impetigo type is more common and both bacteria, staph and strep, can cause this. Nonbullous impetigo appears as red bumps that might look like insect bites. These bumps then transform into miniature blisters that further evolve to pustules. These pustules then form scabs that are akin to honey-colored crust which is the identifying symptom of impetigo. Bullous impetigo. Staph bacteria are the only bacteria that can cause this type. Basically, the bacteria generate a toxin that causes the top skin and the lower layer to separate because of the declining adhesion; this is how blisters form. The term 'blister' in itself is called ‘bulla’ in medical terms, hence the name ‘bullous impetigo’. These blisters could appear in many different spots on the skin, particularly around the torso and buttocks. They also carry a yellowish fluid.