From the photograph, this may be a corn or a viral wart. A corn and a wart can look very similar as they present with an area of thickened skin.
A corn develops due to constant pressure on the skin. This leads to hardening and thickening of the skin.
A viral wart is due to a viral infection of the skin. The virus enters the skin and proliferates, causing an area of thickening of the skin. In a viral wart, tiny red blood vessels can be seen within, which helps to differentiate this from a corn.
When an infection sets in, the area can become painful and red. Topical or oral antibiotics may be needed to treat an underlying infection.
It is advisable for you to see your doctor or dermatologist for a proper assessment to determine the diagnosis and for appropriate treatment.