Eosinophils in the cellular infiltrate of granuloma annulare.

Eosinophils have been described in the infiltrates of granuloma annulare, but their frequency, distribution and extent are not well documented. We found eosinophils in 18/45 (40%) cases of granuloma annulare, without significant variation relating to histologic sub-pattern. Eosinophils were seen in over half the cases of deep granuloma annulare and in over one-third of the cases of superficial granuloma annulare. This study demonstrates the lack of specificity of eosinophils in differentiating superficial granuloma annulare from deep granuloma annulare, granuloma annulare from necrobiosis lipoidica, and granuloma annulare from occasional clinical simulants which histologically show eosinophils, such as arthropod bite reactions.