Perianal lichen dermatoses: A review of 60 cases.

OBJECTIVES

To determine the diagnostic range of lichen dermatoses of the perianus, their extent, and response to treatment.

METHODS

We reviewed perianal biopsies submitted to a tertiary referral pathology service between January 2010 and July 2014, interpreted as 'lichen' or 'lichenoid'. We collected data on patients' characteristics, referring specialty, extent of lesion and response to treatment.

RESULTS

During the study period, 60 perianal biopsies met our inclusion criteria. The distribution of diagnoses was lichen sclerosus (LS) in 25/60 (42%), lichen simplex chronicus (LSC) in 23/60 (38%), lichen planus (LP) in 10/60 (17%), and a non-specific lichenoid reaction in 2/60 (3%). Eleven of 25 cases of LS (44%) showed superimposed LSC. Of 10 LP cases, nine (90%) were hypertrophic and three of these showed pseudoepitheliomatous hyperplasia; none were erosive LP. Compared with patients in the LS and LSC groups, those with LP were more likely to have a localised lesion. Topical steroids were prescribed in 91% cases with treatment data available, and 98% of treated patients who returned for follow up had improved or their disease was resolved.

CONCLUSIONS

We encountered a spectrum of perianal lichen dermatoses, with LS, LP and LSC all represented. LS biopsied at the perianus is often lichenified. Hypertrophic LP is a common form of LP at the perianus.