At the clinic visit, physical examination was notable for scattered pink dermal papules with a dusky red center bilateral dorsal and palmar hands, as well as bilateral conjunctival erythema. (Figure 1). Differential diagnosis included erythema multiforme, acute febrile neutrophilic dermatosis, erythema elevatum diutinum and multicentric reticulohistiocytosis. A punch biopsy was taken from the left index finger.
Histological examination revealed a dense perivascular and interstitial inflammatory infiltrate composed of lymphocytes, histiocytes, and numerous neutrophils with surrounding papillary dermal edema. High power views demonstrated scattered nuclear dust and fibrin within the walls of the small blood vessels with extravasation of red blood cells in the surrounding stroma (Figure 2). The patient’s histopathological findings were most consistent with leukocytoclastic vasculitis (LCV). Upon discussion with the patient’s oncologist, it became known that the patient had received an MMR vaccine two weeks prior to the rash. The patient followed up one week later with a more typical appearing rash for LCV (Figure 3). The rash resolved with use of topical clobetasol ointment and his eyes also cleared. The patient has continued to receive lenalidomide without any recurrence of the rash.