Erythema Marginatum In A Case Of Post-Streptococcal Arthralgia: A Rash Mimicking Urticaria

摘要

Erythema marginatum secondary to streptococcal infection is classically associated with acute rheumatic fever and fulfills one of the Jones criteria for this diagnosis. We describe a case of streptococcal associated erythema marginatum without rheumatic heart disease in a 12 year old male with post streptococcal arthralgia and myalgia. The rash was originally suggestive of urticaria. He was initially seen with a five week history of fever. Examination and laboratory evaluation did not yield an acute infectious etiology for his fever. However anti-streptolysin O and anti-deoxyribonuclease B were very elevated. Historically, he had a sore throat 3 weeks prior to his presentation and had been treated by his PCP with amoxicillin; no cultures were done. Based on this history and his elevated anti-streptococcal antibody titers, he was started on cefadroxil and non-steroidal anti-inflammatory drugs. Several days after antibiotics were started and several weeks after his fever and arthralgia symptoms had begun, he developed a trunk and upper arm rash with raised, erythematous borders. Dermatology diagnosed it as urticaria and cetirizine was recommended. The antibiotic was switched to azithromycin but the rash persisted. He was referred to rheumatology who diagnosed a post-streptococcal syndrome. He was started on penicillin under close observation and no changes in the rash were noted. His aches improved in a matter of days. Dermatology biopsied his rash and the histopathology was consistent with both urticaria and published reports of erythema marginatum. Electrocardiogram and serial echocardiographs were normal. His anti-streptococcal titers returned to near normal in 12 months. His elevated inflammatory markers normalized. This case demonstrates a post-streptococcal syndrome with a rash suggestive of urticaria, but was later confirmed to be erythema marginatum in the absence of carditis. Confirming the diagnosis of erythema marginatum was critical, since it enabled a diagnosis of rheumatic fever which had direct implications for prophylactic treatment. Introduction Post-streptococcal syndromes, such as rheumatic fever and post-streptococcal arthritis, have diagnostic criteria. Many post-streptococcal illnesses may not fulfill diagnostic requirements. The breadth of post-streptococcal syndromes is increasingly apparent. Diagnosing a post-streptococcal syndrome is often difficult, not only in meeting criteria but also making a temporal association with streptococcal exposure. The syndromes may overlap in presentation, may be incomplete, or may mimic other systemic disease. We present a case of temporally related post-streptococcal arthralgia and myalgia with erythema marginatium without evidence of carditis. The rash was initially diagnosed as urticaria. Case Presentation A 12 year old male was admitted with no significant past medical history. He first presented to the infectious disease clinic with a five week history of fevers to 103F and a 3 week history of polyarthralgia and myalgia. The joint discomfort was limited to his shoulders, knees, ankles and his mandible area. The discomfort caused him to miss several weeks of school. The pain partially responded to non-steroidal anti-inflammatory drugs (NSAIDs). His review of systems revealed a history of sore throat 3 weeks prior to presentation, which had been treated with amoxicillin. His exam revealed an antalgic gait but no erythema or joint swelling. In addition, no limitation of joint movement was seen. He had no muscle tenderness or weakness on exam. His cardiac, pulmonary, lymphatic and abdominal exams were normal.His workup included an elevated erythrocyte sedimentation rate of 74 mm/hr (0-15 mm/hr), a c-reactive protein of 8.9 mg/dL (<= 0.5 mg/dL), mild anemia with hemoglobin of 11.5 g/dL (12.5-16.1 g/dL), white blood count of 6700 (4000-12,000) and increased platelets at 587,000 (150-400 10-3/mcL). Computed tomography of his mandible, ultrasound of his abdomen, and radiogr