Functional magnetic resonance imaging in dermatology: The skin, the brain and the invisible.

The skin and brain have a close bi-directional anatomical and functional connection. Historically, the skin-brain axis and the brain-skin axis have been well described. However, brain function in this context has only recently been demystified with the introduction of functional neuroimaging in dermatology. Functional neuroimaging, especially functional magnetic resonance imaging (fMRI), allows indirect visualisation of brain function. This review looks back to the beginnings of functional neuroimaging in dermatology, summarises the currently available dermatology-related fMRI studies and discusses the potential future role of fMRI as a stratifying tool in clinical dermatology and in the development of novel therapies. According to the main body of research made in this field, the focus is placed on experimental itch studies, which described the brain structures involved in itch processing, the regulation of the scratch response, contagious itch and itch suppression.