Mycetoma : Nocardia asteroides
Image Description
This anteroposterior radiograph shows involvement of the distal humerus in a case of actinomycotic mycetoma. The causative agent was Gram-positive bacterium Nocardia asteroides. Note the swelling of soft tissues as well due to cellulitis. Cutaneous or skeletal involvement is rare in N. asteroides infection.
Overall, 80% of nocardiosis cases present as invasive pulmonary infection, disseminated infection, or brain abscess; 20% present as cellulitis. Severely immunocompromised persons are at greatest risk for nocardiosis. These include persons with connective tissue disorders, malignancy, HIV infection, pulmonary alveolar proteinosis, alcoholism, or high-dose corticosteroid use. Image courtesy of: Dr. Libero Ajello, CDC Public Health Image Library.
Overall, 80% of nocardiosis cases present as invasive pulmonary infection, disseminated infection, or brain abscess; 20% present as cellulitis. Severely immunocompromised persons are at greatest risk for nocardiosis. These include persons with connective tissue disorders, malignancy, HIV infection, pulmonary alveolar proteinosis, alcoholism, or high-dose corticosteroid use. Image courtesy of: Dr. Libero Ajello, CDC Public Health Image Library.