Hypersensitivity reaction as a harbinger of acute myeloid leukemia: a case report and review of the literature.

Cutaneous paraneoplastic syndromes comprise a broad spectrum of cutaneous reactions to an underlying malignancy. These dermatoses are not the result of metastatic spread to the skin, but rather a reaction to the presence of malignancy. Cutaneous paraneoplastic syndromes often precede the identification of a malignancy. We describe the case of a 79-year-old man with a six-month history of recalcitrant treatment- resistant dermatitis. A complete blood count test performed at the time of initial presentation was normal. The patient ultimately presented with erythroderma and was diagnosed with acute myeloid leukemia (AML). The evolution of the dermatitis to erythroderma coincided with the clinical presentation of AML, and was therefore considered to be a paraneoplastic syndrome. The patient decided against therapy and died seven weeks after diagnosis. Physicians should consider a cutaneous paraneoplastic syndrome when faced with dynamic recalcitrant dermatoses that are difficult to treat and decide on laboratory testing accordingly. Patients should be evaluated regularly for two to three years after initial diagnosis with a physical exam and review of systems to monitor for signs and symptoms of malignancy.