A rapidly regressed giant plantar wart following biopsy.

Dear Editor:

I read the case reported by Jin et al.1, with great interest, because I recently experienced a rapidly regressed giant plantar wart, which followed a biopsy. A 23-year-old male came to our department for a large hyperkeratotic plaque on his left plantar surface. It appeared more than 18 months prior to the presentation as multiple small pimplelike lesions, which had been slowly growing and coalescing (Fig. 1). His medical and family histories were noncontributory. A punch biopsy was taken, and the histopathological findings were acanthotic epidermis with hyperkeratosis, papillomatosis, parakeratosis, and koilocytes. The diagnosis of wart was made. The lesion rapidly regressed within 2 weeks of the biopsy, and it had completely disappeared when the patient presented for the follow-up after one month (Fig. 2). Warts, or verrucae, are benign proliferations of the skin and mucosa that are caused by an infection with human papillomavirus (HPV). These viruses do not produce acute signs or symptoms, but induce a slow, focal expansion of the epithelial cells. Lesions may remain subclinical for long periods, or may grow into large fulminating masses that persist for months or even years2. The management of warts depends on the degree of physical and emotional discomfort, the extent and duration of the lesions, the patient's immunologic status, and the patient's desire for therapy2. Irrespective of the treatment modality, a host immune response is the key to achieving a complete clearance of the wart. Immunocompromised individuals may never achieve wart clearance. The role of immunity in HPV infection is not completely understood. The decrease in the frequency of warts with age implies that the resistance to infection develops over time, and much of this resistance may be immunologic3. There are instances in which the treatment of one or more warts leads to a complete clearance in immuno-competent individuals. Specific cell-mediated immunity against viral infected keratinocytes took place in plane warts, under spontaneous regression4. CD4-positive lymphocyte predominance in the regression of genital warts had been demonstrated5. Tissue biopsy might have exposed viral antigens to the host immune system, which subsequently triggered HPV-specific immunity. It is possible that the biopsy may have then exposed viral antigens and induced a delayed hypersensitivity reaction, which led to the rapid regression of the lesion. We suggest that a similar mechanism has been in the works in our case. There have been many cases of warts with spontaneous regression, but there has been no report of large plantar wart regression, following a small biopsy. In conclusion, wart regression can be achieved if the HPV-specific immunity can be stimulated. Therefore, inducing and boosting such a response is critical for the treatment of warts. I report here on a case of a rapidly regressed large plantar wart, following a biopsy without any additional treatment.

Fig. 1

Before biopsy; large hyperkeratotic plaque on his left plantar surface (inset: close-up view).

Fig. 2

Six weeks later following biopsy, the wart had completely disappeared (inset: close-up view).