You may have a tumor.
You tell me, you are the Doctor.
That happens to me so often that sometimes I avoid eating oranges. I suspect it's something in the citric acid.
Could be the acidity if u scuffed your skin abit
was the orange sweet ? they're using chemicals to artificially ripen them .
the flesh of an orange is where flesh eating bacteria come from. You didnt know?
Finger nails can be fragile......