AbstractBackgroundLine‐field confocal optical coherence tomography (LC‐OCT) is a new, valid means for a rapid and non‐invasive in vivo examination of the epidermis and upper dermis, allowing digital interpretation and measurement of high‐resolution images on a cellular level. Given these properties, it may represent a valid tool for monitoring psoriasis during treatment, allowing a new method to set a precise objective severity of the disease.ObjectivesWe aimed to investigate the potentialities of LC‐OCT in the non‐invasive monitoring of microscopical changes associated with moderate–severe plaque psoriasis (PP) during the treatment with the most common biological drugs.Materials and MethodsWe performed LC‐OCT imaging of PP lesions from 17 patients before and after 8 weeks of treatment. The clinical severity of the single lesions was evaluated using a lesion score (LS), designed considering three parameters: erythema, desquamation and infiltration. LC‐OCT images were segmented by artificial intelligence and evaluated based on three microscopic criteria: the thickness of the stratum corneum, the thickness of the living epidermis and the undulation of the dermo‐epidermal junction.ResultsLine‐field confocal optical coherence tomography digital analysis allowed recognition and quantification of the three microscopic criteria, showing a reduction of all these during the follow‐up. Furthermore, a high correlation between change in LS and the thickness of the stratum corneum and the thickness of the living epidermis was found.ConclusionLine‐field confocal optical coherence tomography can non‐invasively monitor the response of PP to different treatments. Morphometric changes occurring in the psoriatic lesion during the 8‐week treatment period were identified by in vivo LC‐OCT and measured by using artificial intelligence. Although future studies are required, based on these preliminary results, LC‐OCT may represent a valid potential tool for precise monitoring of therapeutic response.