Histologic examination of the biopsy specimen revealed superficial and deep mixed inflammatory infiltrates composed of lymphocytes, histiocytes, and numerous eosinophils. The epidermis showed areas of spongiosis and a few dyskeratotic keratinocytes, while there was prominent edema of the papillary dermis (Figure 2). There were also collagen bundles surrounded by dense infiltrates of lymphocytes, histiocytes, and numerous eosinophils with their surrounding degranulated contents, creating histologic flame figures (Figure 3). Oral prednisone and cetirizine therapy was initiated, and a 1-week follow-up visit revealed partial resolution of the lesions.
Recurrent, Pruritic Dermal Plaques and Bullae—Diagnosis. Arch Dermatol. 2007;143(6):791-796. doi:10.1001/archderm.143.6.791-f