Corns are small, localized areas of thickened skin that form on the feet in response to repeated friction or pressure. This process, known as hyperkeratosis, occurs when the skin is constantly irritated and produces excess layers of the protein keratin, leading to a dense plaque. Corns are distinct from other common foot lesions because they are typically smaller, deeper, and possess a well-defined central core.
Defining the Appearance of Hard and Soft Corns
Hard corns, medically termed Heloma Durum, are the most common type and present as a firm, dry mass with a polished surface. They are small, concentrated plugs that are usually yellowish or white. They develop over bony prominences, such as the tops of the toes or the outer edge of the fifth toe, where they rub against footwear. The defining feature is a translucent central core, shaped like an inverted cone that presses inward on nerve endings. This deep pressure causes significant pain, often feeling like a stone is lodged in the foot.
Soft corns, or Heloma Molle, look different due to their location and the presence of moisture. They are found exclusively between the toes, most frequently between the fourth and fifth digits. Because sweat is trapped in this interdigital space, the corn absorbs moisture, giving it a characteristic spongy, rubbery texture. Soft corns appear white or gray due to this maceration and may sometimes be ring-shaped. The constant dampness makes them susceptible to secondary bacterial or fungal infections, which can lead to a foul odor.
How Corns Differ from Calluses and Warts
Calluses (Tyloma) represent a broader, more diffuse area of hyperkeratosis, lacking the corn’s defined central core. They form over weight-bearing surfaces, such as the heel or ball of the foot, and are typically larger with ill-defined edges. Unlike corns, which are painful due to their deep, pointed core, calluses are generally painless unless they grow very thick.
Plantar warts are caused by the Human Papillomavirus (HPV) and are contagious, unlike corns and calluses which are caused by friction. Visually, a plantar wart often disrupts the normal parallel lines of the skin, whereas the skin lines usually pass through a corn. Warts may also contain tiny, dark pinpoints, which are clotted blood vessels often described as “seeds.” A simple diagnostic test involves applying pressure: corns hurt most when pressed directly inward, but plantar warts cause sharp pain when squeezed sideways.
Safe Home Care and When to Consult a Doctor
For individuals without underlying health conditions, home care focuses on reducing friction and softening the thickened skin. Non-medicated corn pads or foam toe separators can be used to cushion the area and offload pressure. Soaking the foot in warm water to soften the lesion, followed by gentle abrasion with a pumice stone or foot file, can help reduce the thickness of the corn. Proper footwear that provides ample space and avoids squeezing the toes is essential.
Consult a healthcare professional, such as a podiatrist, if the corn shows any signs of infection, including increased redness, swelling, warmth, or drainage. Individuals with underlying conditions like diabetes, neuropathy (nerve damage), or poor circulation should never attempt to treat corns at home. These conditions can cause minor skin injuries, such as those from filing or medicated treatments containing salicylic acid, to quickly progress into non-healing ulcers and severe infections. Professional evaluation ensures safe debridement and addresses the underlying mechanical or structural cause of the pressure.