Corns, Callosities, and Plantar Warts

Definition of Corns and callosities

Corns and callosities refer to the localized thickenings of the skin that appear over sites of repeated trauma and pressure.

Predisposing Factors

1. Prolonged pressure.
2. Friction.
3. Shearing forces of bone against each other.
4. Ill-fitting shoes.

Clinical Features

Corns are well-demarcated small areas of thickened skin most commonly seen over the dorsolateral aspect of the fifth toe but may be seen at other places also. They are conical in shape with the apex pointing inwards into the tissue and hence are tender on vertical pressure. Paring reveals a central nucleus. Soft corns are located in the third and fourth toe web spaces.

Calluses are diffuse non-tender areas of thickened skin with indefinite borders commonly present in areas of repeated friction. The normal skin markings can be seen over callosities and they lack a central nucleus.

How to treat Corns and callosities

1. Removal of causative factors like ill-fitting shoes or orthopedic deformities.
2. Paring: After softening the affected area with a 40 % salicylic acid dressing under occlusion for 48 hours, the corn/callosity is gently pared with a scalpel blade. Repeat dressing and paring if required.
3. In case of a very painful corn, a small amount of intralesional steroid under it can relieve the pain.

Plantar Warts

Plantar warts constitute 25 to 35 % of all warts. They begin over pressure points like heels, heads of metatarsals, below toes, and the forefoot as small, shiny, sago-grain papules. They soon become well-defined and rounded and develop rough and hyperkeratotic surface with a surrounding collar of thickened horn.

A mosaic wart results due to the confluence of multiple lesions into one large, usually flat lesion.

Clinical Examination

Reveals the skin markings to be discontinuous over the warts.

Diagnosis

Plantar warts may be differentiated from corns and callosities on clinical grounds as outlined above.

Plantar warts treatment

Plantar warts commonly recur despite treatment. Hence, avoidance of nail-biting, use of rubber gloves during swimming and sticking to the use of one’s own towel and clothing can prevent their further spread to other areas and to others. Various modalities of treatment are:

• Occlusive dressing with 40 % salicylic acid followed by paring.

• Electrocautery is better than surgery but scarring and recurrence may occur.

• Cryotherapy, the treatment of choice for all types of warts including mucosal, causes rapid cooling below freezing point followed by thawing, by applying substances like liquid nitrogen and carbon dioxide snow using various types of probes.

For more information consult a warts specialist online --> https://www.icliniq.com/ask-a-doctor-online/dermatologist/warts