Chapter 7: Foot Problems

CALLUSES, CORNS AND WARTS

The diagnosis of localised, tender lumps on the sole of the foot can be difficult. The differential diagnosis of callus, corn and wart is aided by an understanding of their morphology and the effect of paring these lumps (Table 7.1).

A callus (Fig. 7.1) is simply a localised area of hyperkeratosis related to some form of pressure and friction.

A corn (Fig. 7.2) is a small, localised, conical thickening, which may resemble a plantar wart but which gives a different appearance on paring.

A wart (Fig. 7.3) is more invasive, and paring reveals multiple small, pinpoint bleeding spots.

TREATMENT OF PLANTAR WARTS

There are many treatments for this common and at times frustrating problem. A good rule is to avoid scalpel excision, diathermy or electrocautery because of the problem of scarring. One of the problems with the removal of plantar warts is the ‘iceberg’ configuration (Fig. 7.4) and not all may be removed. Pare the wart with a scalpel or file with a pumice stone or emery board prior to treatment.

Liquid nitrogen

1. Pare wart to level of tolerance.

2. Apply liquid nitrogen (use double freeze–thaw cycle).

3. Repeat every 2 weeks until resolved.

Can be painful and results are often disappointing.

Topical chemotherapy

1. Pare wart (particularly in children).

2. Apply Upton’s paste to wart each night and cover.

3. Review as necessary.

4. If preferred, apply topical anaesthetic cream (e.g. EMLA) an hour prior to each episode of paring.

(Upton’s paste comprises trichloroacetic acid 1 part, salicylic acid ...