Onychocytic matricoma: a new, important nail-unit tumor mistaken for a foreign body.

Themechanism for voriconazole-induced photosensitivity andphototoxicity remainsunknown.One current hypothesis includes a potentially phototoxic UV-B–absorbing N-oxide metabolite of voriconazole.4 Alternatively, inhibition of CYP450 with voriconazole therapy is thought to possibly increase serum retinol level, a known photosensitizer.5 Malignant skin conditions associated with chronic voriconazole use, includingmelanoma in situ and squamous cell carcinoma,havebeenreported inpatientswithFitzpatrickskin types IIIorbelowandmorecommonly in individualswithsome degree of immune compromise.1,2 More recently, the development of lentigines in adark-skinnedpatient receiving longtermvoriconazole therapywasdescribed.6Ourpatient is similar in the abrupt development of lentigines andphotodamage characterized bymild poikiloderma but differs from the prior report owing to the severe melanocytic atypia observed. Cutaneous adverse effects of long-term voriconazole therapy are not only burdensome but also lead to morbidity and mortality. Product labeling recommends discontinuation of voriconazole therapy if a squamous cell carcinoma or melanoma develops,1,2 which can lead to adverse outcomes if alternative antifungal therapies are limited. In addition, for patients awaiting transplant, the development of a melanoma also could compromise the ability to receive an organ donation. This report highlights the development of atypical melanocytic lesions in adark-skinned individual receiving concurrent voriconazole and immunosuppression therapy and reinforces the importance of counseling patients on appropriate sun protection and sun avoidance. These patients, regardless of skin type, require frequentdermatologic follow-upand surveillance with a low threshold for biopsy of atypical lesions.