Porokeratosis of Mibelli affecting the lips: A novel ultraviolet-induced fluorescence dermoscopy finding.

Porokeratoses represent a rare spectrum of keratinisation disorders that commonly present as annular, scaly plaques with an atrophic center and either hyper or hypopigmentation. They can be inherited in an autosomal dominant pattern with variable penetrance or occur sporadically. Porokeratosis of Mibelli (PM) is a solitary variant that usually presents in childhood or adolescence and has been attributed to immunosuppression, although the underlying mechanisms remain unclear. Importantly, PM is recognised as a potentially premalignant condition. Ultraviolet-induced fluorescence dermoscopy (UVFD) is a novel, emerging, non-invasive diagnostic tool that can assist in diagnosing various skin lesions. Herein, we report a case of PM affecting the lips, that revealed an unexpected finding on UVFD examination.