Brief Answer:
It needs further evaluation.

Detailed Answer:
Hi,
Welcome to health care magic,

I have read your query and understand your concern,

Here ,I would like to know if there is any history of fever or kidney problem in recent past.

We will need some blood works to make a diagnosis like complete hemogram,ESR,CRP,serum uric acid and RA factor with X- ray of the ankle with foot.

Here, it might be because of arthritis or post viral joint pain but can be said exactly only after the blood reports and clinical examination.

Meanwhile, you can apply volini gel or spray and can take over the counter analgesic and antiinflammatory medications.

I would advice you to see some local doctor or ortho-surgeon who will know all the tests and examine the ankle,foot and black spots on the sole to come at a particular diagnosis.

You can ask me if there is any doubt.

Regards,

Dr.sandipkabra

---