The exact cause is not known.
Some investigators consider it is caused by abnormal sweating.
The condition may be mild with only a little peeling, or very severe with big blisters and cracks which prevent work. The later and more chronic stage shows more peeling, cracking, or crusting. Some patients will have mostly one stage, and some patients will have mostly the other. Some times both stages occur at the same time. Secondary infection with Staphylococcal bacteria is not infrequent.