Bicycling is ordinarily a beneficial exercise for the foot muscles. When bicycle foot results from this exercise it is usually evidence that the bicyclist had an abnormal condition of his foot muscles and foot joints before he took up the exercise in question.
CHAPTER XIV
VERRUCA (WART), CALLOSITY, HELOMA (CORN OR CLAVUS)
DISEASES OF THE NAILS—INGROWN NAIL
VERRUCA OR WART
Definition. A verruca is a circumscribed overgrowth of all the layers of the skin, varying in size from a pin’s head to a small nut. These growths may be single or multiple, and may come and go without any special reason. Verruca plantaris, or plantar wart, is observed on the sole of the foot; it may be single or multiple. It is very painful; it may be the size of a pea and is often mistaken for a callosity, from which it may be distinguished by the pain on pressure, and the tendency to bleed when the horny layer is removed.
Verrucae are probably contagious, but the pathogenic agent has not been isolated. They sometimes disappear spontaneously, and they will recur if their removal is not complete.
Treatment. Certain chemical substances (see “escharotics”) destroy tissue and can be employed with safety only after much experience. These drugs when allowed to spread on the normal skin often occasion painful and persistent lesions. They must therefore be applied directly and sparingly to the growth itself and not be left in contact too long.