What is it?
A corn is a hardening of the skin that is formed as a result of persistent pressure or friction. The skin becomes hardened to protect all of the delicate structures beneath the surface. A Lister's corn is a particular type of lesion that develops along the outer portion of the nail groove. The patient will frequently complain of pain while wearing shoes and will often identify the skin build-up as part of an ingrown toenail.
What causes them?
A Lister's corn is caused by abnormal pressure to the nail groove. This can be from a structured deformity within the toe such as a bone spur, a contracted digit (hammertoe), or abnormal biomechanics (the way one walks). A Lister's corn also can be caused from pressure from tight or improper shoe gear. It is important to recognize a lister's corn because it can lead to an ingrown toenail, infection or ulceration (break down of the skin). Once these lesions become evident, a vicious cycle is set into motion. The skin build-up attracts more pressure and friction to the involved site and thus, the lesion size increases.
How do you treat them?
There are many ways to treat a Lister's corn. First, proper shoe gear should be worn and the shoes should not be tight or ill-fitted. Periodic debridement of the corn should be performed by a podiatrist. Finally, the structural deformity, if present, should be addressed. This might include removal of a bone spur, correction of a hammertoe deformity with surgery or special inserts called orthotics that can be made by your podiatrist. These seemingly simple skin lesions can in many cases, cause extreme discomfort and result in moderate degrees of disability while wearing shoes. A corrective approach to the Lister's corn is in most cases, the recommended treatment of choice.