Not all cases of herpes can be treated with acyclovir cream. If the causative agent of herpes is determined to be a virus and a DNA virus, then topical acyclovir cream can be used. Acyclovir cream is not effective for herpes caused by RNA viruses or herpes caused by bacteria. Regardless of the type of herpes, care should be taken not to break the herpes as much as possible to avoid secondary bacterial infections that could aggravate the condition. It is also important not to eat hairy foods during the illness to avoid increasing herpes.