Erythema migrans spares rash of engraftment syndrome

Abstract

A 65-year-old man with multiple myeloma was admitted for autologous stem cell transplant. He felt well on admission. A physical exam was remarkable for a 1-centimeter erythematous indurated lesion on his right flank at the site of an "insect bite" sustained 4 days before admission. After tolerating melphan conditioning, he received stem cell infusion. Four days later, the lesion developed into a 6-centimeter indurated erythematous ovoid rash with central clearing and a punctate area in the middle (Fig. 1) which grew to 30-centimeters over the next few days. Although, the differential diagnosis for target lesions includes tinea corporis, leprosy, and lupus erythematosus, our patient's large solitary lesion was classic for erythema migrans. From the