Blisters in diaper area not from a burn?

http://www.thenewparentsguide.com/diaper-rash.htm

See section on Impetigo.


Impetigo: This type of rash can appear as yellow-brown crusty patches or pus filled pimples or blisters, which is usually accompanied by a lot of surrounding redness. This rash can cover the buttocks, lower abdomen, anus, umbilical cord, and thighs and then spread to other parts of the body. Impetigo is caused by bacteria (streptococci or staphylococci). If you think your baby's rash is a bacterial infection, be sure and notify your doctor immediately. Your doctor will most likely prescribe a topical or oral antibiotic.