Hi, Thanks for using HCM.
One of the reason could be due to underling hair line bone fracture
or infection of subcutaneous tissue
If there is infection you need antibiotic treatment,
You need to rest your foot, you need splinting of toe for rest.
Consult your orthopedic surgeon for examination and management.
Hope I answered your question. Feel free to ask me if you have any further queries.
Wish you good health. Take