Warts, Herpes Simplex, And Ot... Health Article

Corns are a mechanically induced lesion that forms over or under a weight-bearing surface or structure. Corns (clavi) over the metatarsal heads are frequently mistaken for warts. The two entities can be easily distinguished by paring the callus with a #15 surgical blade. Warts lack skin lines that cross their surface and have centrally located black dots that bleed with additional paring. Examination with a hand lens shows a highly organized mosaic pattern on the surface (see Figure 12-4). Clavi or corns also lack skin lines crossing the surface, but they have a hard, painful, well-demarcated, translucent central core (Figure 12-17, A). The core or kernel can be removed easily by inserting the point of a #15 surgical blade into the cleavage plane between normal skin and the core, holding the scalpel vertically, and smoothly drawing the blade circumferentially. The hard kernel is freed by drawing the blade horizontally through the base to reveal a deep depression (Figure 12-17, B). Pain is greatly relieved by this simple procedure. Lateral pressure on a wart causes pain, but pinching a plantar corn is painless.

The treatment of corns is targeted at reducing the friction or pressure at a specific location. This can be accomplished with orthotic therapy and/or surgical correction of the osseus deformity creating the mechanical pressure point. Podiatric or orthopedic surgeons familiar with biomechanics and reconstructive surgery perform these corrective procedures.

Horizontally arranged clusters of blue-black dots (ruptured capillaries-petechiae) may appear on the upper edge of the heel or anywhere on the plantar surface following the shearing trauma of sports that involve sudden stops or position changes (Figure 12-18, A). It is caused by the shearing force of the epidermis sliding over the rete pegs of the papillary dermis. At first glance, this may be confused with a wart or acral lentiginous melanoma, but closer examination reveals normal skin lines, and paring does not cause additional bleeding (Figure 12-18, B). The condition resolves spontaneously in a few weeks.

Warts in the process of undergoing spontaneous resolution, particularly on the plantar surface, may turn black (Figure 12-19) and feel soft when pared with a blade. Cell-mediated immunity against virus-infected keratinocytes may take place in the process of regression of some warts.

Keratolytic therapy with salicylic acid (DuoPlant gel [salicylic acid in flexible collodion], Occlusal-HP liquid [salicylic acid in polyacrylic vehicle], and many others that are now available over-the-counter) is conservative initial therapy for plantar warts. The treatment is nonscarring and relatively effective but requires persistent application of medication once each day for many weeks.

The wart is pared with a blade, pumice stone, or sandpaper (emery board). The affected area is soaked in warm water to hydrate the keratin surface; this facilitates penetration of the medicine. A drop of solution is applied with the applicator and allowed to dry. Solution may be added as needed to cover the entire surface of the wart. Penetration of the acid mixture is enhanced if the treated wart is covered with a piece of adhesive tape. Inflammation and soreness may follow tape occlusion, necessitating periodic interruption of treatment; consequently, the patient may be satisfied with the longer, more comfortable process of simply applying the solution at bedtime. White, pliable keratin forms in a few days and should be pared with a blade or worn away with abrasives such as sandpaper or a pumice stone. Ideally, the white keratin should be removed to expose pink skin; to accomplish this, an occasional visit to the office may be necessary.

This is a safe, nonscarring treatment similar to keratolytic therapy with salicylic acid liquid except the salicylic acid has been incorporated into a pad. Salicylic acid 40% plasters (Mediplast and many others) are particularly useful in treating mosaic warts that cover a large area.

The plaster is cut to the size of the wart. The backing of the plaster is removed and the sticky surface is applied to the wart and secured with tape. The plaster is removed in 24 to 48 hours, the pliable white keratin is reduced in the manner previously described, and another plaster is applied. The treatment requires many weeks, but it is effective and less irritating than salicylic acid and lactic acid liquid. Pain is relieved because a large amount of keratin is removed during the first few days of treatment.

Blunt dissection is a surgical alternative that is fast, effective (90% cure rate), and usually nonscarring. It is superior to both electrodesiccation-curettage and excision because normal tissue is not disturbed. ¹¹

The immunomodulating drug imiquimod (Aldara cream) is more effective on thicker keratinized (nongenital) skin when occluded and used in combination with cryotherapy or a keratolytic agent. ¹² It is essential to debride the thick scale before applying imiquimod. The patient applies the cream daily and covers with tape (for ≥12 hours) to enhance penetration. Response to the use of imiquimod on the plantar surface is usually not preceded by an inflammatory reaction.

Suggestive therapy generally works through the age of 10 years. A banana peel, potato eye, or a penny applied to the skin and covered with tape for a 1- to 2-week period has been effective in young children. Another technique is to draw the body part on a piece of paper and then draw a picture of the wart on the diagram. Crumble the pictures and throw them in the wastebasket.

Some physicians have had success by treating children with vitamin A 10,000 U for 4 to 6 weeks.

Cantharidin mixtures are very effective for plantar warts. Apply Canthacur PS (cantharone plus podophyllin 5% plus salicylic acid 30%) in the office and allow to dry. Avoid touching normal skin. Cover with occlusive tape (e.g., Blenderm) or Moleskin and remove in 24 hours or earlier for significant discomfort. A blister usually appears. Patients can relieve pain by breaking the blister. Patients may apply moleskin or felt padding around but not over the lesion to reduce pressure. In 2 to 3 days, remove the blister under local anesthesia by scissors excision or curette. Retreat weekly if necessary.

Various lasers are available for treating resistant warts. The procedure is expensive and at times painful.

For years a variety of acids has been successfully used to treat plantar warts. This technique is occasionally used to treat warts that have recurred after treatment with other techniques and occasionally used as initial therapy. Like keratolytic therapy, repeated application is required. Home application of acids is too dangerous; therefore, weekly or biweekly visits to the office are required. A number of acids may be used (bichloracetic acid is commercially available).

Treatment is as follows. The excess callus is pared. The surrounding area is protected with petrolatum. The entire lesion is coated with acid and the acid is worked into the wart with a sharp toothpick. This procedure is repeated every 7 to 10 days.

This may be considered for resistant cases. Mosaic warts or other large involved areas may be treated with daily soaking for 30 minutes in 4% formalin solution. The firm, fixed tissue is pared before subsequent soaking. Lazerformaldehyde solution (10% formaldehyde) is commercially available for direct application to warts. There is a risk of inducing sensitization to formalin.

Cryosurgery on the sole may produce a deep, painful blister and interfere with mobility. Repeated light applications of liquid nitrogen are preferred to aggressive treatment. Cryotherapy is equally effective when applied with a cotton wool bud or by means of a spray. ¹³ A surgical blade is used to debulk the wart before freezing. Liquid nitrogen is applied until ice-ball formation has spread from the center to include a margin of 2 mm around each wart. A double or triple freeze-thaw cycle may be more effective than a single freeze. Treatment is given every 2 to 4 weeks for up to 3 months.

See the section on common warts.

Intralesional bleomycin may be considered when all other treatments fail. The drug is expensive. Three milliliters of bacteriostatic saline is added to a 15-U vial of bleomycin sulfate (Blenoxane; Bristol-Myers). The solution is transferred into an empty 20-ml vial, to which an additional 12 ml of saline is added to produce a total of 15 ml of solution of 1 U/ml. This vial now becomes a storage container. A 3-ml syringe is filled, capped, and refrigerated. The solution will remain stable for 4 weeks. After the induction of local anesthesia with topical EMLA cream (lidocaine and prilocaine), one or two drops of the bleomycin solution is dropped onto the wart and ‘pricked’ into the wart using a Monolet or 25-gauge needle until bleeding points appear. The site is covered with a plastic bandage strip, which is removed that evening or the next day. The patient returns in 2 weeks for additional treatment. The responsive warts show hemorrhagic eschars that heal without scarring. Blackened or macerated tissue is removed with a blade, and the bleomycin is readministered. A 92% success rate was achieved. ^{14, 15} The use of bleomycin for the treatment of warts results in significant systemic drug exposure; therefore, it is prudent to exclude pregnancy before treating women of child-bearing age. ¹⁶ The patient can be given a prescription for the drug and bring the medication to the office; insurance companies will often pay for the medication if it is obtained at a pharmacy.

The tips of the fingers and toes are a confined area. Therapeutic measures that cause inflammation and swelling, such as cryosurgery, may produce considerable pain.