This can be callus or corn formation.
They are hard, thickened areas of skin that form as a consequence of rubbing, friction or pressure on the skin.
As you wear work boots so it can cause friction.
Most corns and calluses gradually disappear when the friction or pressure stops, if you have to wear your boots then custom-made padded shoe inserts (orthotics) inside your boots can be helpful.
Properly positioned moleskin pads can help relieve pressure on affected area.
You can try OTC a patch containing 40 percent salicylic acid (Callus Remover, Clear Away, others).
Avoid scratching it with clippers.
Walk barefoot whenever possible, especially at home.
Soaking feet in warm water and filing the callus down with a pumice stone gently to smooth thickened skin.
Apply moisturiser on affected area also.
And see a podiatrist if it recurs again.
Hope this helps.
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