How are they formed?
Corns are fairly similar to callus formation, and usually present alongside. But they are located where all the pressure concentrates most: over a bony prominence, like the large ball of the foot; and other areas of the forefoot, like the metatarsal heads of the lesser toes. Singular pressure in the form of compression, along with other forces can interact too, in creating them. The layers of the skin are compacted, but unlike the shearing which prevents the layers becoming too compact, the compressional emphasis causes the skin to form a conical shape over the high pressure area.
These can be exceptionally painful, since the tip of the cone will push into the body, towards the bone in most cases. Enucleation (removal) by a podiatrist, will alleviate the discomfort almost immediately; and we can also prescribe padding or palliative insoles, to help remove areas of high stress, specific to the areas of the feet we are dealing with. Incidentally, it may be a result of poor natural mechanics, that causes someone to be prone to areas of high pressure, because of their foot function. So the podiatrist may prescribe a functional insole, to alter the motion of the foot, during the gait cycle.
There are also multiple types of corns; the most widespread being hard corns. There are seed corns too, which affect mainly the heel, and are less painful. These afflict people with very moist feet. Regarding footwear, these people would benefit greatly by getting a breathable shoe, or boot, that allows plenty of evaporation to help minimise the excessive moisture.
There are those corns on the top of the toes, that occur as a result of poor fit mechanics, or poorly fitting shoes (mainly the shoes). These are the ones patients complain about most, and can be difficult to go. They are sometimes hard, with callus formation from the friction from shoes, or may be soft and fluid like. Either way, for years, corn plasters and other corn solutions have been manufactured, and sold for treatment. The reality is, however, that most of these solutions essentially remove the upper layer of the corn, and nothing else. In many cases, needle aspiration, or surgical intervention, is required by a surgeon, to treat with such. In only some instances, these types could be managed by a podiatrist, when assessed.
More painful than the standard heloma durum (hard corn), are the vascular and neuro-vascular ones, and these are the bad boys! These usually have been persistent for a long time. What makes them worse, is the pain; it is significantly sharper, and the area is prone to being hypersensitive. Vascular corns are those that through repeated trauma, have on a cellular level, developed a small circulatory supply. This then sustains the area longer, which ironically is not what is needed. It also has the added effect of liquid pressure entering the area, as the blood circulates through the micro-vessels. The biggest issue is when trying to get rid of them. Some can self-correct, if the pressure is removed, and regular debridement (skin shaving), is undertaken to have the thinner skin layers on top of the vessels reduced. However, because the nutrient supply enriches the area, once the corn has been enucleated, the skin grows back very quickly, which would be good in wound healing, but in this instance, the pressure quickly reforms the corn in question. They also bleed excessively, and therefore are liable to form even more capillaries, under the corn and skin. If the cycle is not dealt with soon, it can become a nightmare to manage.
Though almost identical to the vascular, neuro-vascular corns, have a peripheral nerve, or multiple peripheral nerves, which become involved with the corn. Touching it can be excruciating, and what makes these the most difficult, is that reduction with a scalpel, would require administering a local anaesthetic. The corn area tends to suffer so much trauma from the repeated debridement (normally from incorrect or attempted self-treatment), and the enucleation, that it eventually scars as well. Even off-loading the pressure, only minimises the pain. The hypersensitivity of the area will only disappear, once the nerve involvement is removed, (if indeed it can be removed), a very challenging situation. It may be that if the involvement is too complex, referral to a consultant may be needed, for possible surgical excision.
Finally, interdigital compression (between the toes) development can occur, when toes press upon each other, usually from poor fitting footwear. The moisture between the digits is higher normally, so debridement of the mass requires a more delicate touch, as it is very easy to debride too deep and cause a haemorrhage.
Controlling Your Corns
Essentially, it is important to note that you should not allow corns to get to a bad stage. Hard skin and corns, are big warning signs early on, about the direction and magnitude of forces passing through your feet. If your footwear is protective, well cushioned and supportive, and you are still getting corns, it’s time to book in with a Podiatrist for a biomechanical assessment, to determine the cause of your issues. Keeping the skin well moisturised helps too, as it reduces the reoccurrence of the corns, by allowing the compression taking place between the layers to microscopically move more, thus reducing the severity of the corn being formed. Breathable footwear, with comfortable socks, is another point worth noting. One should aim to avoid footwear, that might shift your body weight on to one area of the foot; those that have really high heels, for example.
Your feet mirror your general health . . . cherish them!