I'm not sure what this could be? Is it fungus maybe dry skin infection?
Dry skin is normal to have at this point, regardless of getting the flu. As long as it starts to go away over the next week or two and isn't accompanied by other symptoms like burning, redness, swelling, etc. then I wouldn't be concerned. Always check with your doctor though, since they know the specifics of your case.
Dry skin is treated with a good lotion with a lanolin base. By applying it a few times a day, the dryness will be addressed