Tyloma and Pinch Callus
A Callus refers to a localized thick area on the sole of the foot. When the skin is exposed to persistent friction or pressure, it protects itself by increasing the thickness of its external layer. This external hard layer is made up of dead skin cells, which acts as a protective covering or cap over the underlying viable skin layers.
A callus is often caused by:
An ill-fitting or uncomfortable shoe, pressing against the toes and sole of the foot, or by faulty foot biomechanics, leading to some areas being exposed to a greater amount of pressure.
A callus can form anywhere on the skin, but is more common in the areas which lack sufficient cushioning from fatty tissue, such as the skin over bony prominences. Calluses are commonly found on the ball of the foot and heel.
A pinch callus or tyloma refers to the formation of a callus along the ridge of skin that is pinched. An example of this is on the inner side or under side of the big toe joint. It usually occurs as a result of a big toe functional deformity called hallux limitus, which is characterised by a stiff big toe joint.
Due to the stiff big toe joint, the toe does not flex during walking, and to overcome this restricted movement a person usually rolls off the inner side of the foot. As the foot rolls outwards the skin on the inner side of the big toe joint gets pinched, rubbing against the inside of the shoe, which leads to the formation of a pinch or spin callus, also called hallux pinch callus (hallux = big toe).
A pinch callus may cause pain and discomfort during walking. Moreover, in diabetics and people with poor circulation, calluses may be followed by skin ulceration, therefore proper evaluation and treatment is essential.
Use comfortable footwear and padding to prevent further irritation. Professional debridement of the callus can reduce its size and thus the discomfort that it causes.
Treating the cause of the problem:
Proper management includes correcting the underlying condition. If the underlying hallux limitus is not treated, the pinch callus will continue to reform.