Eosinophils in lichen sclerosus et atrophicus

Background The classic histopathologic features of lichen sclerosus et atrophicus (LS) include lymphoplasmacytic inflammation below a zone of dermal edema and sclerosis. The presence of eosinophils in LS has received little attention, but the finding of tissue eosinophils, particularly eosinophilic spongiosis in LS, has been suggested as a marker for the coexistence of autoimmune bullous disease or allergic contact dermatitis (or both). We sought to determine whether the histopathologic presence of dermal eosinophils or eosinophilic spongiosis (or both) in biopsies from patients with LS is associated with autoimmune bullous disease, autoimmune connective tissue disease or allergic contact dermatitis. Methods A retrospective review of the histopathology and medical records of 235 patients with LS who were evaluated from June 1992 to June 2012 was performed. Results Sixty-nine patients (29%) had eosinophils on histopathology. Among patients with associated diseases, a statistically significant association between the eosinophil cohort and the cohort without eosinophils was not detected. Conclusions The importance of eosinophils is uncertain, but our data suggest that the finding of tissue eosinophils alone is not sufficient to prompt an extensive workup for additional diagnoses.