DISSEMINATED BLASTOMYCOSIS PRESENTING AS MONOARTICULAR SEPTIC ARTHRITIS

Abstract

TOPIC: Chest Infections TYPE: Medical Student/Resident Case Reports INTRODUCTION: Blastomycosis is a dimorphic fungus that causes acute or chronic pneumonia with extrapulmonary involvement in a minority of cases. Rarely it is implicated in disseminated disease causing joint involvement leading to septic arthritis. Recognizing blastomycosis as an important cause of septic arthritis and starting treatment is necessary to prevent joint destruction and overwhelming disseminated infection. CASE PRESENTATION: A 29-year-old male with no significant past medical history presented to the hospital with chief complaint of right knee pain of 3 weeks' duration associated with recent onset of productive cough, dyspnea on exertion and chest pain. Admitting vitals were remarkable for tachycardia and fever of 101 F. Physical examination revealed right knee swelling and pain on active and passive range of motion without overlying erythema. Joint aspiration revealed 68,000 WBC with 88% neutrophils with negative crystals. Cultures from synovial fluid grew blastomyces dermatitidis. During the hospital stay, patient's respiratory status worsened, and he was transferred to the ICU and intubated. CT Chest showed diffuse bilateral pulmonary nodules, suspicious for atypical pneumonia versus acute respiratory distress syndrome. Bronchoscopy was done and specimens were sent for culture. He was initially started and then maintained on broad spectrum antibiotics. Once respiratory and synovial cultures grew blastomyces, patient was started on IV amphoterecin. Patient's condition improved dramatically after starting amphoterecin. His remaining ICU course involved extubation, tracheostomy and gradual weaning of pressors. His knee pain and swelling subsided after starting amphoterecin and patient was discharged to rehab in stable condition on itraconazole. DISCUSSION: This case highlights the rare presentation of disseminated blastomycosis as monoarticular septic arthritis. About 3% of patients with blastomycosis have joint involvement. Extrapulmonary blastomycosis is usually seen in association with pneumonia which can often be severe enough to cause ARDS and shock, like our patient. It is important to have a high index of suspicion for blastomycosis in patients presenting with septic arthritis with an active pulmonary process and B symptoms. Diagnosis of blastomycosis is with culture, urinary and serum antigens. Treatment involves amphoterecin B followed by itraconazole for patients with severe disseminated disease. CONCLUSIONS: Disseminated blastomycosis can present with symptoms of extrapulmonary spread of disease. Diagnosis is with antigen identification in serum and urine and by culture. Treatment involves amphoterecin B and itraconazole. REFERENCE #1: Chapman, Stanley W., Andrew C. Lin, Katherine A. Hendricks, Rathel L. Nolan, Mary M. Currier, Ken R. Morris, and Helen R. Turner. "Endemic blastomycosis in Mississippi: epidemiological and clinical studies." In Seminars in respiratory infections, vol. 12, no. 3, pp. 219-228. 1997. REFERENCE #2: Wheat, L. J. "Antigen detection, serology, and molecular diagnosis of invasive mycoses in the immunocompromised host." Transplant infectious disease 8, no. 3 (2006): 128-139. DISCLOSURES: No relevant relationships by Fatima Ayub, source=Web Response No relevant relationships by Muhammad Hasib Khalil, source=Web Response