Callus – intractable plantar keratosis (IPK)

What is n painful calluses (IPKs)?

An IPK is a type of painful callus that forms in areas of high pressure typically underneath the metatarsal heads. These IPKs are very painful and cause forefoot pain referred to as metatarsalgia. 

Why do painful calluses (IPKs) develop?

IPKs develop in areas of high pressure secondary to the foot structure and biomechanics, another reason is that there is a loss of the fat pad underneath the metatarsals. As people get older they lose fat on the bottom of the foot that provides cushioning. Certain foot types such as flat feet and high arches cause abnormal amounts of pressure underneath the foot in certain areas. 

Where are the common places to develop painful calluses (IPKs)?

If you have a flatfoot the most common places are below the 2nd and 3rd metatarsal heads. In people with high arches common places are the 1st and 5th metatarsal heads. Patients with hammertoes can develop IPKs at distal part of their toes.

How to prevent and treat painful calluses (IPKs)?

The most important part about treating IPKs is to address the biomechanical forces that are causing increased pressure with using orthotics and supportive shoes. Offloading pads can be placed on the shoe insert or custom orthotics can be made with offloading built in. Typically debridement of the callus is needed in order to remove the thick layer of skin and removal of the core, afterwards the use of salicylic acid is used. Routine maintenance is recommended with creams such as urea and at home debridement with a callus file or pumice stone. This will often treat the IPK, but may return depending on whether the etiology of the increased pressure was addressed. Surgery can be done and that would involve addressing the issues causing the increased high pressure whether it’s a reconstruction, hammertoe correction, lengthening of the achilles tendon, metatarsal osteotomies.