This patient is suffering from a rather mundane affliction, the plantar wart. Named for its obvious physical location, these warts are common and may be seen in up to 10 percent of the population.
Plantar warts are hyperkeratotic eruptions, usually caused by the human papilloma virus (HPV types 1, 2, and 4), and are found on the plantar surface of the foot. These lesions can cause pain isolated to the plantar foot or even referred pain to other parts of the lower extremity. The pain may result in posture and gait abnormalities, and related symptoms may actually be the patient's presenting complaints.
Plantar warts are usually found over areas of the foot subjected to the most pressure — the heel and ball of the foot. Plantar warts are usually self-limited problems, and treatment should be aimed at reducing symptoms and decreasing the duration of the wart's presence. For persistent or extensive warts, dermatologic or podiatric referral may be necessary.
In the emergency department, treatment may include the use of topically applied keratinolytics and/or cauterizing agents. To this end, salicylic acid or dichloroacetic acid applications may be helpful. Compound W, Freezone, and Wart-Off are some common brand products containing salicylic acid that may be useful in treating this condition.
Topical salicylic acid acts to induce desquamation of the horny layer of skin while not destroying normal epidermis. Dichloroacetic acid acts by penetrating and cauterizes skin and keratin. Either of these modalities may be offered to the patient. More extensive surgical treatment is often best done in settings other than the emergency department.