Posted 18 Jul

All about corns

What is a corn? 

A corn is a pinpoint area of hard skin that develops because of compressive and torsional forces.

Our skin has two main layers, the dermis and epidermis. The epidermis is the most superficial layer and is made up of 5 different layers of keratinocytes. The function of this layer is protection from environmental damage, it can help reduce water loss and helps to protect us from infectious substances such as bacteria and viruses.

The deeper layer of the skin, named the dermis, is a thicker later of connective tissue housing the blood vessels, nerve endings, hair follicles and sweat glands. This layer is capable of much more, such as aiding in thermoregulation, sensation, supplies nutrients and plays a vital role in wound healing.

In the beginning phases a corn sits in the outermost layer, the epidermis and is formed by bundled up keratinocytes. When the skin is subject to continuous, repetitive friction, compression or tensile forces, the keratinocytes bundle together resulting in a callus or corn formation.

They typically form over the metatarsal heads or other bony prominences such as toe joints. On the outer edges of the foo this is typically formed due to ill-fitting footwear, particularly in the winter months when we tend to wear more constrictive footwear. Plantar foot corns generally develop all year round due to the biomechanics and anatomical positioning of our feet.

Are there different types of corn?

There are several different types of corns however the most common are heloma durum corns. These are purely corns that develop because of excessive pressure and consist of only keratinocytes.

They feel like a pebble or a foreign body stuck in the foot. These corns, if not treated can develop into a more serious type of corn, known as a neurovascular corn. These are generally more painful as the tissue from the dermis has started to grow into the epidermis, and vice versa.

Why do corns keep returning when they removed?

As corns develop due to excessive pressures and forces, if we don’t remove the cause (excessive forces) the corn will often return.

How to treat them?

There are 3 options when we talk about treating corns, this is divided into short term and long term management plans.

Short term debridement: Many people attend podiatry appointments for their corns regularly debriding/removing. This offers instant pain relief as the hard lump of keratinised skin has been removed from the area.

Long term offloading: Customised bespoke foot orthotics can offload corns and calluses through altering one’s biomechanics. A perfect example would be corns that develop under the 2^nd metatarsal head (ball of the foot). We often develop corns here as our foot arch collapses, which reduces the pressure under the big toe joint. The pressure is then shifted over to the 2^nd metatarsal head resulting in overload. Customised orthotics can restore the function of the big toe and reduce pressure under the 2^nd metatarsal which in turn reduces how quickly the corn returns.

Surgical removal of corns: When long standing corns have become neurovascular, they are often too painful to debride deep enough to conservatively remove the excess tissue. Surgically removing the corn will cut off the vascular and nerve supply, while removing the entire lesion under local anaesthetic. This result can be both short term, and long term in nature depending on the lesion itself.

Our podiatrists here at Flawless Feet are here to sit down and talk you through a full treatment plan designed for your condition and lifestyle. Not everyone’s corns are the same which is why you should seek an expert opinion first!

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