Ex vivo confocal laser scanning microscopy (ex vivo CLSM) provides rapid, high-resolution imaging of excised skin samples as well as a digital hematoxylin-eosin (H&E)-like staining. Furthermore, immunofluorescence examination can be performed using fluorescent-labeled antibodies. In this study, we aimed to assess the diagnostic accuracy of ex vivo CLSM in identifying histopathological features and basal membrane (BM) fluorescence with fibrinogen in lichen planus (LP) and as lupus band test in cutaneous lupus erythematosus (LE), as well as to compare its diagnostic accuracy with conventional histopathology and direct immunofluorescence (DIF) microscopy. 33 sections of 17 LP patients were stained with acridine orange (AO) and fibrinogen, and 72 sections of 18 LE patients were stained with AO, IgG, IgM and IgA. Subsequently, ex vivo CLSM examination in reflectance, fluorescence and digital H&E staining modes was performed. 
Ex vivo CLSM identified most frequently interface dermatitis (94.1%), band-like (94.1%) and perivascular infiltration (82.4%) in LP sections, whereas perivascular infiltration (94.4%), interface dermatitis (88.9%), and spongiosis (83.3%) were the most common features in LE. Fibrinogen deposition along BM was detected with DIF microscopy and ex vivo CLSM in 93.75% and 62.5% of LP patients, respectively. A complete lupus band was identified in 83.3% of LE patients with DIF microscopy, however in 22.2% of patients using ex vivo CLSM. 
In conclusion, ex vivo CLSM enables simultaneous and rapid identification of histopathological and immunofluorescence findings in LP and LE in the same examination session, albeit with a lower detection rate than DIF in detecting BM fluorescence.

Advanced diagnosis of inflammatory skin diseases: simultaneous immunofluorescence and histopathological assessment in cutaneous lupus and lichen planus using ex vivo confocal laser scanning microscopy