Warts & Treatments

Viral warts or plantar warts are very common skin conditions that are found in children and adults.

Human papillomavirus (HPV), a DNA virus, is responsible for plantar warts. On the extremities, the subtypes are 1, 2, 4, 27 and 57. Damage to the skin and transient impairment in the immune response is necessary for these lesions to form

.

HPV can exist in showers, spas, swimming pools.

Places with abrasive non-slip surfaces can be high-risk areas for both harboring the virus and causing skin abrasion. 30-40 % of HPV warts infection can clear up spontaneously but those that do not are not only cosmetically unappealing but also painful. This can cause pain in shoe gear, walking barefoot.

The virus promotes basal cell proliferation. Hyperplasia of the granular and prickle cell layer occurs along with dermal papillae moving upwards placing its vasculature up into the wart. Thickening of Keratinocytes, with a nucleus surrounded by the divergence of skin lines at the lesions, shows viral damage to the cells.

 

Plantar warts

Are clinically painful well-circumscribed lesions with hyperkeratosis. After debridement of the thickened skin, pinpoint bleeding may be noted and interruption of skin lines. Pain is present when one performs lateral compression of the plantar lesion but the area is also painful when ambulation with direct pressure. If the wart part of the nail unit, the nail may become thickened and dystrophic.

Multiple treatments are available but none of them are specific to eradicating an HPV strain.

Treatment Plan

At this time there is no single treatment technique and no specific antiviral therapy has been developed, plantar warts are hard to handle for both clinicians and patients.

Different treatment plans have been described in the literature

: tissue keratolysis (salicylic acid)

: immunotherapy (bleomycin)

: tissue destructive (cryotherapy, surgical excision).

Eradication is ultimately through the activation of the body’s immune response to recognize the viral particle as foreign.

Salicylic acid

A keratolytic dissolves the epidermis. This is usually the first line of treatment that many podiatrists may choose to start with. This is usually done at home after an initial debridement/cryotherapy in the office. Patients are advised to do this daily along with occlusion (cover with bandaid/duct tape). From a cost-benefit/success rate this is a very effective treatment and most lesions may resolve with this treatment plan.

Cryotherapy

This is another first-line treatment and is performed in the office. Usually done with liquid nitrogen or CO2 liquid spray to freeze the lesion. This may be painful since there is a local inflammatory response to cryotherapy. But this is transient and most patients tolerate the procedure well. This is usually done every 10-14 days along with topical treatments.

Cantharidin

This is a second-line treatment for which first-line treatments have failed. Cantharidin (Cantharone), is a blistering agent, derived from the beetle Cantharis vesicatoria. After the initial debridement, one would apply a thin layer of cantharidin and then cover the wart with occlusive tape. After 8-24 hours wash the area with soap and water. Afterward, a blister may form so don’t be alarmed. This is again repeated once every two weeks. Although the application itself is noted painful the blister may cause discomfort. Literature has shown cure rates of up to 80 percent.

Aldara

It is an immunomodulatory therapy that enhances cell-mediated immunity. Previously this drug was approved for basal cell carcinoma, superficial squamous cell carcinoma, and anogenital warts. Two studies have shown daily application for 5 days/week for 16 weeks showed clearance rates of up to 80%

Bleomycin

DNA and protein synthesis inhibitor has antiviral, antibacterial, and antitumor properties. This is reserved for recalcitrant warts that have failed previously listed treatment. This treatment causes tissue destruction which then will cause an immunological response. Pregnant women or those breastfeeding, vasculary, and immunocompromised patients should avoid this treatment. This can be painful therefore is usually administered in the OR or with Local anesthesia. Although bleomycin has high rates of effectiveness but may not be the ideal therapy for every patient.

 

Surgical treatment options

If all treatments have failed surgical excision is the next go to step. This involves complete excision of the lesion, curettage followed by cauterization, or a true excisional procedure.

This can usually be performed with a laser as an adjunctive therapy. There are different laser modalities on can employ which include a CO2 or Nd: Yag laser. Laser therapy alone has a 78 percent cure rate in literature.

The major problem with surgical intervention is the formation of scar tissue and healing time as the area where the lesion has been excised has to heal.

Another surgical procedure that has gained popularity is taking a portion of the lesion and implanting it into the muscle belly such as the adductor hallucis or Gastroc. The increased blood supply is thought to introduce a better immune response. Studies done with implantation have shown a high cure rate. But further research is needed to confirm these results.

 

In Summary

Plantar wart infections of the skin are complex and interesting diseases. Wart treatment is not just about destruction to the skin lesion but causing and immune response so that the body can recognize the infection. The goal of therapy is to get rid of the lesion and get the patient back to ambulating without pain.

Multiple therapies exist, but one needs to have a treatment algorithm. Starting with the simple debridement all the way to surgical intervention for recalcitrant lesions. Using a combination of therapy can lead to positive outcomes in patients and lead to better results.