Looking from the photo, the skin lesions can be the result of flea or insect bites. The initial itchy red spots will heal over time and will form these dark marks. These marks can take many months to fade. The treatment will include:
- Topical steroid and antibiotic cream for the active bites
- Medical grade lightening cream for the brown marks. This will help the marks to fade faster
- Anti-itch tablets. Take these if necessary to help with the itch
It is always advisable to see a trusted doctor or dermatologist for a proper assessment as well as early management. Hope this helps!