Erythrocyte sedimentation rate (ESR) as a laboratorial marker for therapeutic response in acute osteomyelitis

Abstract

 Introduction: osteomyelitis is a potentially serious inflammatory infectious bone pro­cess which can lead to sequelae. Staphylococcus aureus is the main etiological agent and the most common clinical manifestations include: irritability, fever, phlogistics signs and pseudo­paralysis. Diagnosis depends on clinical suspicion, and complementary tests, such as ery­throcyte sedimentation rate (ESR), may aid in diagnosis. Objective: to present a case of acute osteomyelitis in infant and to discuss the importance of ESR as a laboratory tool for the diagnosis of this condition and for monitoring the response to the treatment. Case description: eightmonthold infant, previously healthy, presented functional impotence in the right shoulder, joint edema and fever after an episode of phlebitis during hospitaliza­tion for acute bronchiolitis. In the blood culture there was growth of community associated methicillin resistant Staphylococcus aureus (CA-MRSA). Image exams revealed bone and joint involvement, and laboratory tests corroborated the diagnosis of acute osteomyelitis. She underwent venous vancomycin treatment for six weeks and oral clindamycin for two weeks, presenting favorable clinical and laboratory evolution. Discussion: ESR is a nons­pecific laboratory test, but used as an aid in the diagnosis of various conditions. It is useful in documenting the inflammatory process, assessing the degree of extension, and in some cases, as a follow-up of the treatment response. In addition, ESR is the most sensitive la­boratory test in the diagnosis of osteoarticular infections, since it’s usually increased from the initial stage of the disease, contributing along with clinical and radiological aspects, to its diagnosis and treatment control.