면역 기능의 이상이 발견되지 않은 영아에서의 침습성 녹농균 감염증 2례

Two Cases of Invasive Pseudomonas aeruginosa Infection that Developed in the Apparently Immunocompetent Infants

침습적 Pseudomonas 감염은 대개 면역 저하 환자들에서 발생하며, 이는 높은 사망률과 관련이 있다. 그러나 드물게는 면역력이 정상인 숙주에서도 발생할 수 있다. 첫 번째 증례는 괴저성 농창과 Pseudomonas 패혈증이 발생한 5개월 여아이며, 두번째 증례는 9개월 남아에서 지역사회 감염으로 발생한 폐렴과 Pseudomonas 패혈증이다. 두 환아 모두에서 녹농균이 배양검사로 증명되어 감수성 있는 항생제를 사용하였으며, T 림프구, B 림프구, 보체, 식세포 등 면역력에 대한 검사는 모두 정상이었다. 저자들은 이전에 건강했던 영아들에서 발생한 침습성 녹농균 감염증 2례를 경험하였기에 이를 보고하는 바이다.

Invasive Pseudomonas infections most often occur in the immunocompromised patients and are associated with high mortality rate. Rarely this disease may develop in healthy infants and children. We report two cases of invasive Pseudomonas aeruginosa infections that were diagnosed in otherwise healthy infants. The first case was a previously healthy 5-month-old infant with ecthyma gangrenosum and septicemia. She presented with fever, swelling of left periorbital area and multiple erythronodular skin lesions. Each skin lesion formed a black eschar surrounded by an erythematous areola over time. Cultures of blood, urine and discharge from skin lesions grew P. aeruginosa. On the day of visit, she showed pancytopenia which was normalized after 10 days. The patient responded well to the management with ceftazidime and tobramycin. The other case was a previously healthy 9-month-old infant with community-acquired pneumonia. He was referred from an outside hospital with fever and cough. Chest x-ray revealed pneumonic infiltrations on both lower lungs with pleural effusion on the right side. Cultures of blood and pleural fluid grew P. aeruginosa. Chest CT performed on the ninth day demonstrated pneumatoceles, lung abscess and necrosis of lung parenchyma. He was managed with ceftazidime and amikacin for 50 days. No residual pulmonary complications were noted during the three month follow-up. Laboratory results to evaluate immunologic defects of phagocytic cells, complement components and T- and B-lymphocytes were all within normal range in both patients. It should be kept in mind that Pseudomonas can be, though uncommon, a cause of community-acquired invasive infections in the previously healthy infants.