Exploring Alternative Treatment For Resistant Warts
A Closer Look At The Etiology
And Diagnosis Of Warts
Plantar warts are epidermal lesions caused by an infection by the human papilloma virus (HPV). Over 100 subtypes of HPV have been identified. The subtypes commonly found in plantar warts are HPV 1, 2, 4 and 10.
The HPV virus is transmitted between hosts through direct contact. For infection and replication to take place, the virus requires a compromised skin surface with epithelial cells in an advanced state of differentiation. The virus attacks the granulosum and keratin layers of the epidermis. The viral DNA and protein production occur in the upper spinous layer with final virus assembly occurring in the granular layer.11
HPV is a non-enveloped, double-stranded DNA virus that replicates in all epithelial cell layers. However, viral replication is associated with excessive proliferation of all of the epidermal layers except the basal layer. This process produces acanthosis, parakeratosis and hyperkeratosis. There is also a deepening of the rete ridges, which produces the typical papillomatous architecture that produces pinpoint bleeding with debridement of the lesion.
Plantar warts occur most frequently in children and young adults. One study suggests that the persistence of disease may be attributable to a lack of Langerhans’ cells at the site of the lesion, leading to decreased stimulation of cell-mediated immune response.12 Minor trauma at the site of inoculation may be important as there could be an abrasion of the skin that allows penetration of the wart into the epidermis. Warts will frequently be present in high-pressure or high-friction areas that are often otherwise occupied by calluses.
Though one can diagnose warts with a high degree of certainty based on their clinical appearance, a biopsy may be required for a definitive diagnosis. If a lesion is chronic, aggressive, irregular and resistant to multiple therapies, be cautious of possible malignancy. In rare cases, warts may degenerate into verrucous carcinomas.13
The key to success for treating the recalcitrant wart is combination therapy. It’s also essential for patients to take an active role in their treatment. We will commonly incorporate a home therapy of 5-fluorouracil cream with tape occlusion and thorough debridement both in the office and by the patient with a pumice stone.
Additionally, we will commonly prescribe cimetidine 400 mg TID and educate patients to take vitamin A and zinc supplements daily. Patients should expect to take these medications for at least three months. A study by Orlow and Pallor showed an 81 percent success rate in eradicating warts in children with cimetidine alone in three months.9 A similar study revealed only a 30 percent success rate among adults.10
When using the above treatment modalities and combination therapy, we infrequently need to implement more aggressive treatments like surgical excision and laser treatments. Furthermore, the aforementioned conservative modalities do not have as much pain and morbidity associated with them. Although there is a certain place for surgical curettage and laser treatments, there are times when these approaches are impractical. In conclusion, we have had great success with a conservative approach in treating the recalcitrant wart by employing combination therapy.
Dr. Salk is the Director of Research at the Northern California Foot and Ankle Center. He is in private practice in San Francisco and Santa Rosa, Ca.
Dr. Chang is Chief of the Department of Podiatric Medicine and Surgery at the Sutter Medical Center in Santa Rosa, Ca. He is a Clinical Professor at the California School of Podiatric Medicine at Samuel Merritt College. He is a Fellow of the American College of Foot and Ankle Surgeons and is a faculty member of the Podiatry Institute.
Dr. Grogan is a Research and Surgical Fellow at the Northern California Foot and Ankle Center, and practices in San Francisco and Santa Rosa, Ca.
Dr. D’Costa is Chief of Staff-Elect at the Sutter Medical Center in Santa Rosa, Ca., and is in private practice in Santa Rosa, Ca.