Line-field confocal optical coherence tomography for the differential diagnosis of porokeratosis from clinical simulators: a preliminary study.

Porokeratosis variants are relatively rare and can be clinically misdiagnosed with several common papulo-keratosic simulators. Line-field confocal optical coherence tomography (LC-OCT) is a new technology able to explore the skin in vivo up to 500µm depth. In this preliminary study we aimed to investigate the role of LC-OCT in the diagnosis of many porokeratosis variants. A total of 54 patients (28 was affected by one among 13 porokeratosis variants, 26 had a simulator condition) were examined at lesional and perilesional sites in vertical and horizontal view. We found an almost perfect interobserver agreement in LC-OCT images interpretation and a perfect correspondence with histologic slides. In addition, a series of morphologic in vivo and 3D features related to the cornoid lamella were detected by LC-OCT, not visible under histology. This device can be proposed for rapid bed-side non-invasive differentiation of porokeratosis variants from their simulators, possibly sparing incisional biopsy in doubtful cases.