Callouses

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Since man began wearing shoes, he has been troubled with callouses generally on the bottom of the feet. These callouses are very similar to corns on the toes but are generally larger and more superficial. In some instances these callouses can be small and very hard as in the case of a plugged sweat gland. For ages, we have treated these with razor blades and pads generally unsuccessfully.

What is the problem?

Callouses generally have the same cause as the corns....internal and external pressure on a small area of the skin. The internal pressure comes from the underlying bones and the external pressure is the ground or the sole of the shoe. Because we are walking on the soles of the feet, any callous will feel like walking on a stone. There are two kinds of callouses;

Friction or Pressure Callouses: The bone structure on the "ball" or pad of the foot is made of the ends or heads of the long bones of the foot or the metatarsals. Under normal conditions, these metatarsal heads each bear an equal amount of weight Figure 1. Because of injuries to the metatarsal heads, this equal bearing of weight changes and one or more of the metatarsal heads bears more weight then the rest Figure 2. When this happens, a callous will develop under that metatarsal head.

Porokeratosis: A porokeratosis is actually the plugging of the duct that leads from a sweat gland to the surface of the skin. This is generally plugged with callous. When this occurs, the fluid in the tube and sometimes in the gland dries up and becomes very hard. These porokeratosis cause a pain that feels like walking on a tack.

What can be done?

Friction or Pressure Callouses: If the cause of the callous is principally internal pressure from the bones, it would stand to reason that if the pressure on this bone were removed, the callous would go away. This is absolutely true! In the milder cases, an orthotic can be used to "offload" this metatarsal head. In more severe cases, a surgical procedure is done to "raise" the metatarsal head slightly Figure 3 and Figure 4.

Porokeratosis: When a porokeratosis is discovered, the only cure for this is to remove this lesion. This is done as an office procedure where under local anesthetic, the lesion is removed. This does not require sutures nor does it require special footgear. This generally heals very quickly.