I am glad that your ultrasound
of the leg is normal. It seems like it is a superficial skin rash
or a dermatological condition manifesting as a erythematous rash
. Even though, the ultrasound is normal the possibility of a superficial clot cannot be ruled out.
It could be the beginning stage of a trophic ulcer due to the Neuropathy in your feet.
The MS could be discharging small emboli as well.
1. Make sure MS is managed best.
2. Continue the medications for Neuropathy.
3. Apply ice packs to the locally affected area.
4. Mild to moderate physical activity has proven beneficial. This should not be restricted.
Get well soon.