Hello,
If it is painful and has pus then it is possible that it is due to an infection. But if it is itchy then it can be due to pompholyx. Pompholyx is also called dyshidrotic eczema. It is characterized by a sudden onset of many deep-seated pruritic, clear vesicles which itch and then peel off. As a result the skin may also fissure.
To confirm the diagnosis I suggest you to get it evaluated from a dermatologist.
I hope it helps. Take care and regards.
sounds like a spot? is it an infection?