Spontaneous Regression of Palmar Warts after Suffering from
Verruca vulgaris (VV) is a common skin disease caused by human papilloma virus (HPV) infection. Contact immunotherapy with several sensitizing chemicals, such as diphenylcyclopropenone (DPCP) or squaric acid dibutyl ester (SADBE), has been used for the treatment of recalcitrant or multiple warts. Here, authors report a case of multiple VV on the palm that spontaneously resolved after suffering from diffuse contact dermatitis against alkyl bromide.

A 25-year-old Japanese man visited our clinic complaining of rashes on the right thigh. He had been engaged in chemical experiments, and 12 days before the visit (hereafter referred to as day 0), he had spilt alkyl bromide on his right thigh. On day 1–2, erythema with tiny vesicles had appeared on the thigh, and on around day 7, he had complained of fever and vomiting, and the erythema had spread over the trunk. He had visited a dermatologist nearby and then had been referred to our clinic (on day 12).

He presented uncircumscribed erythema on his right thigh. The erythema on the trunk had disappeared by this time. At the same time, we noticed that several warts on his left palm, which he had suffered from for years in spite of multiple cryotherapies, had turned brownish. Histological analysis of the right thigh revealed massive infiltration of lymphocytes and vacuolar changes of the epidermis. Based on these clinical and histological observations, we diagnosed him with contact dermatitis with systemic symptoms and prescribed a topical steroid (clobetasol propionate) ointment. The rashes on the thighs had disappeared by the visit on day 21, and by his next visit on day 50, all the VV on the palm had resolved. Based on this clinical course, we considered that the VV on his palm had spontaneously regressed due to an immunological mechanism.

In conclusion, this case accidentally mimicked contact immunotherapy against multiple VV. VV sometimes regress spontaneously, which may be triggered by accidental contact dermatitis, as shown in our case.

Source: https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7923719/