SESSION TITLE: Infectious Disease Student/Resident Case Report Posters I
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: P. aeruginosa is a gram-negative, rod-shaped ubiquitous bacterium that is found in the environment. It has become an important nosocomial pathogen, especially in patients with compromised host defense. Pseudomonal community acquired pneumonia (CAP) is rare and usually reported in patients with underlying malignancy, cystic fibrosis, aplastic anemia, COPD and bronchiectasis.
CASE PRESENTATION: A 60 yr-old Hispanic female with past medical history of type 2 diabetes mellitus presented to the emergency department with a six-day history of dry cough, right upper back pain, subjective fever and shortness of breath on exertion. She was a non-smoker and denied any recent travel, weight loss or night sweats. On admission, she was afebrile and vital signs were stable. On physical exam, she was noted to have decreased breath sounds in the right upper lung fields. Leukocyte count was 33 x 103/L with 80% PMN. CT scan of the chest showed a right upper lobe cavitary lesion. She was started on ceftriaxone and azithromycin for possible CAP. The next day she developed multiple pustular, erythematous nodules on her lower extremities. Skin biopsy on Day 4 of admission showed extensive subcutaneous fat necrosis, suppuration and abscess formation; indicative of infection. BAL and blood cultures obtained on admission failed to show any organisms. HIV test was negative and serum complement and immunoglobulin levels were normal. She underwent CT-guided biopsy of the cavitary lesion with cultures as well as incision and drainage of several skin nodules, which grew P. aeruginosa with identical susceptibilities. She received 2 weeks of intravenous Piperacillin- Tazobactam with normalization of the leukocyte count (8 x103/L) and resolution of skin lesions.
DISCUSSION: P. aeruginosa has been classically associated with ecthyma gangrenosum, which is most frequently described in the setting of bacteremia in immunocompromised patients. To our knowledge, this is the first reported case of blood culture negative pseudomonal skin and cavitary lung infection in an immunocompetent host. The presentation of our case was unique as the patient did not have any risk factors, such as history of smoking or exposure to aerosolized water, except diabetes mellitus (HbA1C 5.9).
CONCLUSIONS: Although P. aeruginosa CAP in a previously healthy individual is rare; it is often rapidly progressive with a high mortality rate. In a healthy patient presenting with severe CAP with a history of diabetes mellitus; P. aeruginosa must be considered in the differential diagnosis. Early isolation of the organism and initiation of combination therapy with anti-pseudomonal agents is the cornerstone of successful treatment.
Reference #1: Hatchette TF, Gupta R et al.Pseudomonas aeruginosa community-acquired pneumonia in previously healthy adults: case report and review of the literature. Clin Infect Dis. 2000 Dec;31(6):1349-56
Reference #2: Garau J, Gomez L.Pseudomonas aeruginosa pneumonia.Curr Opin Infect Dis. 2003 Apr;16(2):135-43
DISCLOSURE: The following authors have nothing to disclose: Debjit Saha, Danielle Selema, Janella Leon, Seth Gottlieb
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