(Footcare) says corns can be hard or soft. Hard corns are found mainly on the top, tip, or side of toes where constant pressure is applied. Soft corns are usually found between the toes. All corns can be painful, but soft corns generally more so.
Different types of corns need slightly different treatments.
For heloma durum, following disinfection of the foot, remove callus by minute dissection with a scalpel and try to take out the nucleus. Protective padding to relieve pressure may be used. Advice should be given on foot wear. (patient.co.uk/ health) states tight or poor fitting shoes are thought