Verruca Pedis the common plantar wart is not just a viral lesion kept to the population of small children and swimmers. The foreign body can appear on any individual regardless of social status, amount of exposure to the viral particles or age. Plantar warts have the ability to spread quickly among those who are immune-suppressed, those under-going radiation therapies, chemotherapy, and transplants of organs or HIV positive.

The interventions used to treat plantar warts vary tremendously, some cause pain, some do not but all seem to have the same aim and duration of treatment regardless of that which is chosen. Within this article we make an overview of the treatments available, what the evidence states and how the plantar warts come to be.

Proliferation at the prickle cell layer is a result of the infected cells of the basal layer undergoing increased mitosis; this eventually leads to an exaggeration of the papillae of the dermo-epidermal junction. This occurrence encourages terminal capillaries to be drawn towards the superficial layers of the skin resulting in the vascularity of the warts. The Vascularity of the warts is often presented as dark pin prick spots within the lesion which may bleed when debrided.
Sonographic imaging of healthy plantar skin has revealed showed a bilaminar parallel hypoechoic structure with a virtual hypoechoic space in between. Blood flow is depicted as thin venous vessels within the subcutaneous tissue (Wortsman, Sazunic, & Jemec, 2009). Alternatively, infected tissues showed an endophytic (invaginating structure) which was hypoechoic and involved both the epidermis and superficial dermis layers. Arterial vessels are present in at the bottom of most lesions.
Post treatment it is not uncommon for warts to reappear following successful treatment. It is often difficult to remove the entirety of the wart leaving a source for further infection in the future (Watkin, 2006).

Verruca Pedis (VP) are the most common dermatological infection. They appear as round keratotic surfaced benign lesions with well defined limits and deep extension into the superficial layers of the skin due to external pressures during gait. VP are a cutaneous presentation of HPV (human papilloma virus) with a prevalence of approximately 5% in children and adolescents, with females at higher risk than males (Nuno Manuel Pinto, 2010). There is a high transference rate of the virus if regular tissue comes in contact with the infection.
Diagnosis is generally a straight forward procedure, however, if the wart has been previously treated, is not responding to intervention or is not clinically relatable then it is important to not discount the following possibilities.
HPV is indirectly linked with epithelial malignancy; these growths tend to be severely painful, red, discoloured and swollen with growth characteristics. Plane warts which can appear on the plantar or dorsal aspects of the foot have the potential to transform into a rare and extremely autosomal recessive disorder known as Epidermodysplasia verruciformis.
Although not common in podiatry circles, plantar warts can be mistaken for corn or callus, alternatively it has been seen that some practitioners have mistaken a corn or callus for a wart and performed similar treatments.

Treatment can be derived as unnecessary due to spontaneous resolution being found in over 50% of cases within 2 years, however if causing pain, irritation or aesthetically displeasing then treatment can be justified. No particular treatment has been found to be 100% effective and therefore the use of a combination of treatments may yield better results (Watkin, 2006).The following are examples of commonly used treatments which have minimum limitations;
Salicylic acid dissolves intercellular cement and therefore desquamation of without affecting the epithelial cells.
Duct tape has a number of theories attached to its use although evidence remains weak at best, however, it is said that the duct tape occludes the wart and activates the immune system of the body to attack the wart. Additionally, the tape then acts as a debriding agent on removal.
Cryotherapy freezes the area using liquid nitrogen on cotton buds or nozzled spray after the area of concern has been debrided via scalpel. This occurs at a minimum of once every three weeks and is disputed about its use on small children given the amount of pain associated with it.
Essential Oils – wintergreen, lavender, lemongrass and peppermint have all been mentioned to have a positive outcome on plantar warts during a case study of a immune-suppressed patients who was contraindicated to most other treatments.
Homologous Auto-implantation aims to induced healthy cell mediated immune responses through the use of an 18 gauge needle removing a depth of wart tissue and placing it sub-cutaneously.
Needling Methods can be used to once again spark a strengthened immune response.

All methods have a similar goal in the treatment of plantar warts which is to increase the body’s immune response while additionally removing the superficial layer of the plantar wart. After reading the evidence I have begun to use the following treatment procedure for the Verruca pedis is as follows but can be modified to the clinical presentation and needs of the patient;
Debridement of over lying callus until such time as capillary bleed is achieved.
Donut padding created from 5mm felt which is then filled 60% Salicylic Acid (Upton’s Paste)
Dressed with Hypoallergenic taping and rigid sports taping for better hold
Education is to keep area dry for 2 days before removing and soaking feet nightly for 20min before applying duct tape. This is to be repeated until next consult where the process will be repeated until such time as the Verruca resolves.

Conclusion
In conclusion, the evidence for any particular intervention associated with plantar wart treatment is not strong. Questions remain about how aggressive a treatment should be, the timing between treatments and what constitutes the need for treatment given that such a high percentage of the lesions regress within a two year period.
Nonetheless, given the highly contagious nature of the HPV and the human emotive to have reduced concern for others who may be susceptible to contracting the virus, elimination of existing exposures is important for those who are at risk of spreading the contamination further.

Next month FootNotes Blogging will look at an Overview of Stress Fractures, Part One of our Pain Series and our next athlete interview. Until then, thank you for reading and take care.

Jackson McCosker
Director /Chief Editor

References

Coates, C. M., Boehm, A. P., Leonheart, E. E., & Vlahovic, T. C. (2006). Malignant Transformation of Plantar Verrucae. Advances in Skin and Wound Care , 384 – 385.

Forbes, M. A., & Schmid, M. M. (2006). Use of OTC Essential Oils to Clear Plantar Warts. The Nurse Practitioner , 53- 57.

Longhurst, B., & Bristow, I. (2013). The Treatment of Verrucae Pedis Using Falknor’s Needling Method: A Review of 46 Cases. Journal of Clinical Medicine , 13 – 21.

Murley, G., & Perrin, B. (2011). Dermatology Resource Manual. Bundoora: University Erlangen Department of Dermatology.

Nuno Manuel Pinto. (2010). Treating Plantar Warts: What to do When Patients Take Maters into Their Own Hands. Nursing Times .

Shivakumar, V., Okade, R., & Rajkumar, V. (2009). Autoimplantation Therapy of Multiple Warts. Indian Journal of Dermatol Venereol Leprol , 593 – 595.

Watkin, P. (2006). Identifying and Treating Plantar Warts. Nursing Standard , 50-54.

Wortsman, X., Sazunic, I., & Jemec, G. B. (2009). Sonography of Plantar Warts. Journal of Ultrasound Medicine , 787 – 793.