Cutaneous Septic Embolism Presenting as Erythematous Plaques

Abstract

Dear Editor: Intravascular devices such as prosthetic vascular grafts are therapeutic tools of fundamental importance for patients with several vascular diseases. Due to the expanding usages of these devices, incidences of infectious complications are also increasing. The skin can be one of the first sites where signs of sepsis can appear. It is important to be aware of the different clinical features of septic emboli in order to detect them early. An 'erythematous plaque' eruption due to septic embolism from an infected prosthetic aortic graft is being reported. A 62-year-old man was being admitted to the emergency room with a 5-day history of fever and an erythematous plaque on his right thigh. The patient was an ex-smoker and had a history of arterial hypertension, chronic renal failure and ischemic heart disease. Five years ago, he required an amputation below his right knee and implantation of prosthetic vascular grafts due to severe peripheral vascular diseases. Physical examinations revealed painless, warm, erythematous and edematous plaques with poorly defined borders on the right thigh (Fig. 1). Fig. 1 Erythematous and edematous plaques with poorly defined borders affecting the right leg of the patient. Blood tests showed increased plasma creatinine (3.2 mg/dl; reference: 0.3~1.3 mg/dl) and C-reactive protein (26.76 mg/dl; reference: <1 mg/dl) with 89% neutrophilia. Chest X-rays and urine sediments were normal. A skin biopsy was performed showing intraluminal neutrophil thrombi in the deep dermis vessels, suggesting cutaneous septic embolism (Fig. 2). Fig. 2 (A) Skin biopsy showing deep dermis vessels with luminal occlusion due to the presence of neutrophils and fibrinoid material (H&E, ×20). (B) Detail at high magnification showing an intraluminal neutrophil thrombus in the deep dermis vessels ... Blood and skin cultures were negative. Transthoracic echocardiography showed no signs of infective endocarditis. computed tomography angiography, positron emission tomography scan and leukocyte scintigraphy showed collections in the inguinal and abdominal perivascular prosthetic grafts. Piperacillin/tazobactam plus vancomycin were prescribed with good initial responses. He also underwent surgical replacement of the vascular prosthesis, but died of dehiscence due to the new prosthesis two days after the surgery. The culture of the infected vascular graft was positive for Streptococcus viridans. Bacterial endocarditis, infected pseudoaneurysm after endovascular procedures and infected endovascular devices are the most frequent sources of infected emboli, which can lodge to distal vascular trees causing skin lesions. Clinical findings of cutaneous septic embolism are variable: palpable purpura, petechiae, hemorrhagic plaques, pustules, nodules, digital cyanosis and livedo reticularis have been described. Osler nodes and Janeway lesions are special forms of septic emboli presentations, commonly associated with bacterial endocarditis1. On the other hand, erythematous plaques have been poorly described in the literature2. Cutaneous septic embolism biopsy determines the presence of thrombus of neutrophil in dermal blood vessels, although bacteria are usually not detected3. Once the diagnosis of infected emboli in patients carrying vascular devices is made, empiric broad-spectrum antibiotic therapy should start immediately4. Imaging studies should be performed to locate the infected focus for optimal surgery. Our patient presented erythematous plaques due to infectious emboli with no evident of clinical signs of sepsis. Histopathology aids us to establish a diagnosis. Unfortunately, the patient died after the surgery. Erythematous plaques eruption should be taken into account as a clinical form of cutaneous septic emboli.