My 5 year old daughter was complaining that her foot hurt.  We looked at it and she has a pimple like (with white head) bump on the bottom of her foot.  It is almost like a white head, but it has a green color in the middle of the white head.  Im guessing she may have gotten a splinter or something, but Im not sure.
Reclothe Green or black part in the center of white of an abscess is called puncture. The assess formation is mostly due to secondary infection following any cut injury. Putting the feet in hot saline water will help in softening and Chat Doctor. Apply antibiotic ointment like mupirocin after cleaning with Betadine antiseptic solution. Oral antibiotic like amoxicillin will help in healing the lesion. Regards