Fluorescent fibre-optic confocal imaging of lesional and non-lesional psoriatic skin compared with normal skin in vivo

Skin Res Technol. 2012 Nov;18(4):397-404. doi: 10.1111/j.1600-0846.2011.00585.x. Epub 2011 Nov 24.


Background/aims: Fibre-optic confocal imaging (FOCI) allows non-invasive visualization of live skin in vivo. A contrast agent, a fluorophore, is injected in the dermis. FOCI images are optical sections from a horizontal (en face) view. The aim was to study epidermis and the cellular structure of keratinocytes of psoriatic plaques and adjacent non-lesional with healthy skin as a reference.

Methods: Twelve patients with stable plaque psoriasis were studied and compared with a control group of eight healthy individuals. Fluorescein sodium was used as fluorophore. A hand held fibre-optic laser scanner (Stratum(®); Optiscan Pty., Melbourne, Australia) was used. The study included morphometric analyses.

Results: The confocal in vivo images demonstrated characteristic features of epidermis and keratinocytes in lesional and non-lesional skin vs. healthy skin. Morphometry based on FOCI demonstrated an approximately 30% increased width of keratinocytes of psoriatic skin vs. healthy control, and the number of keratinocytes per viewing field was reduced. FOCI allowed non-invasive visualization of cell nuclei and parakeratosis of psoriatic epidermis. The horizontal width of dermal papillae of psoriatic skin was increased by approximately 50% as compared with healthy skin, and the flow of erythrocytes in the papillar vessels could be observed in real-time.

Conclusion: FOCI can directly visualize essential epidermal structures of plaque psoriasis in vivo, in real-time and with cellular resolution without the need of taking biopsies and thus without disturbing the natural state of the skin. FOCI is a versatile future tool for non-invasive microscopic diagnosis and therapy follow-up of psoriasis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Dermoscopy / instrumentation*
  • Equipment Failure Analysis
  • Female
  • Fiber Optic Technology / instrumentation*
  • Humans
  • Male
  • Microscopy, Confocal / instrumentation*
  • Microscopy, Fluorescence / instrumentation*
  • Middle Aged
  • Psoriasis / pathology*
  • Reference Values
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Skin / pathology*