The scars that you have are pigmented scars due to inflammation and injury to the skin caused by the flea bites.
Treatment will be a combination of:
- lightening creams and
- pigment lasers.
Untreated, these scars will eventually fade. However, these scars can take a long time to do so. It may take up to several months or even, more than a year.
Medical treatments (as mentioned above) are aimed to quicken this fading process. Thus, improvement can be seen as quickly as within a month. There are many types of pigment lasers available. Therefore, you should always consult a doctor.