OBJECTIVE:

To assess the evidence for Borrelia burgdorferi sensu lato infection in patients with lichen sclerosus by focus-floating microscopy.

SETTING:

Dermatology department of a university hospital.

DESIGN:

Tissue sections were stained with a polyclonal B burgdorferi antibody using standard histological equipment and then scanned simultaneously in 2 planes: horizontally in a serpentine-like pattern and vertically by focusing through the thickness of the section, ie, focus-floating microscopy. Part of the material was also investigated by Borrelia-specific polymerase chain reaction.

PATIENTS:

The study population comprised 61 cases of lichen sclerosus and 118 controls (60 negative controls and 68 positive controls).

MAIN OUTCOME MEASURE:

The presence of B burgdorferi sensu lato within tissue specimens.

RESULTS:

Using focus-floating microscopy, we detected Borrelia species in 38 of 60 cases (63%) of lichen sclerosus and in 61 of 68 (90%) of positive controls of classic borreliosis, but Borrelia species were absent in all negative controls. Borrelia species were detected significantly more often in early inflammatory-rich (31 of 39 [80%]) than in late inflammatory-poor (7 of 21 [33.3%]) cases (P = .001). Polymerase chain reaction findings were positive in 25 of 68 positive controls (37%) and negative in all 11 cases of lichen sclerosus and all 15 negative controls.

CONCLUSIONS:

Focus-floating microscopy is a reliable method to detect Borrelia species in tissue sections. The frequent detection of this microorganism, especially in early lichen sclerosus, points to a specific involvement of B burgdorferi or other similar strains in the development or as a trigger of this disease.