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

Background: Porokeratosis variants are relatively rare and can be clinically misdiagnosed with several common papulokeratotic mimickers. Line-field confocal optical coherence tomography (LC-OCT) is a new technology able to explore the skin in vivo up to a depth of 500μm. Objectives: To investigate the role of LC-OCT in the diagnosis of many porokeratosis variants in a preliminary study. Method: In total, 130 LC-OCT images were obtained from 98 patients, 45 affected by a porokeratosis variant (69 images) and 53 with a mimicker condition (61 images). Results: We found almost perfect interobserver agreement for LC-OCT image interpretation and perfect correspondence with the findings from histological slides. In addition, a series of morphological in vivo and three-dimensional features related to the cornoid lamella were detected by LC-OCT that were not visible from the histology. Conclusions: This device can be proposed to assist with rapid bedside noninvasive differentiation of porokeratosis variants from their mimickers, possibly sparing incisional biopsy in patients where the diagnosis is uncertain.