Codeine caused pruritic scarlatiniform exanthemata: patch test negative but positive to oral provocation test

Sir, Epidermal grafting with suction blisters is used in treatment of stable vitiligo. Previous reports have shown various complications including postinflammatory hyperpigmentation, peripheral hypopigmentation and hypertrophic scarring. However, the risk of infection has not been reported to date. We report an unusual case of verruca vulgaris that appeared after epidermal grafting. It seems likely that virus particles might have been transferred from the operator, who had verruca vulgaris on his hand, to the patient during the surgical procedure. A 12-year-old girl with localized stable vitiligo was treated by epidermal grafting. Blisters on the recipient site formed within 24 h after three freeze±thaw cycles with liquid nitrogen. Blisters on the donor site were made by suction on the inner portion of the thigh. After approximately 3 h of suction at 200 mmHg, large unilocular bullae appeared. After removal of the blisters at the recipient site, the epidermal sheets were grafted to the denuded recipient site and held in place. Two weeks after grafting, once weekly systemic psoralen-ultraviolet A treatment was started. Almost complete repigmentation was observed 3 months after grafting. Four months after grafting, the patient noticed two verrucous plaques in the grafted site (Fig. 1). She denied warts on any other body sites. There was no history of similar lesions in her family or close friends. The operator, who wore gloves, had a verrucous papule on his hand during the surgery. Skin biopsy of two different lesions, on the patient's back and the operator's hand, demonstrated histological features of verruca vulgaris. Human papillomavirus (HPV) typing was not performed. Although epidermal grafting appears to be an effective and safe method for the treatment of vitiligo, various complications have been reported, of which some are associated with the application of liquid nitrogen, such as postinflammatory hyperpigmentation, hypertrophic scarring, peripheral hypopigmentation and uneven pigmentation. Koebner phenomenon and recurrence have also been considered complications of epidermal grafting. The possibility of transmission of virus from patient to patient or from patient to doctor has been reported. One study showed that virus may survive on a cotton swab dipped into liquid nitrogen and suggested that virus transmission from patient to patient may occur via this route. Charles and Sire reported the possibility of transmission of papovavirus indirectly by cotton-tipped applicators which had been used earlier to treat verruca in other patients. In our case, the same liquid nitrogen and cotton-tipped applicators were not used for multiple patients. Bergbrant et al. reported that there is a risk of contamination of the operator by HPV DNA, during both carbon dioxide laser and electrocoagulation treatment. Once an individual has been infected, new warts may develop in sites of inoculation over a period of weeks to months. After experimental HPV inoculation, it requires from 2 to 9 months for a verruca to become clinically apparent. This observation implies a relatively long period of subclinical infection. In our patient, the verruca appeared 4 months after grafting. It is unclear whether the verruca vulgaris resulted from direct contact with the operator's hand during the surgical procedure, or with another person after grafting. However, there are several possible mechanisms of viral transmission from the operator to the patient: the operator may have palpated the lesion with his bare hand immediately after cryosurgery to evaluate the effectiveness of the freezing, or transmission may have occurred during application of a dressing after surgery. We suggest that the risk of transmission of infection from doctor to patient should be considered as a new complication of epidermal grafting.