Eosinophilic cellulitis (Wells' syndrome): histologic and clinical features in arthropod bite reactions.

Five patients are described with the clinical and histopathologic picture, including flame figures, of eosinophilic cellulitis (Wells' syndrome). Two of them had documented tick bites in the center of these expanding annular lesions, and the histologic picture showed the diagnostic flame figures of Wells' syndrome (eosinophilic cellulitis). A third patient had a clinical picture suggestive of a tick bite reaction but stated she was stung by a small garden bee at the involved site. The fourth patient removed a spider from the site of a spider bite, and this nodule also histopathologically was identical to that of eosinophilic cellulitis. Our fifth patient presented with papular urticaria of flea bites. We suggest that the characteristic flame figures of eosinophilic cellulitis (Wells' syndrome) are not diagnostic of a specific disease entity but rather a striking and peculiar histopathologic response to multiple factors of which arthropod bites (ticks, bees, fleas, and spiders) represent one definite etiology.