Nocardiosis Clinical Presentation

Clinical manifestations of nocardiosis depend on the site of infection.^{[5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16]}

• Primary cutaneous nocardiosis may present as cutaneous infection, lymphocutaneous infection, or subcutaneous infection.

  • Cutaneous nocardiosis generally manifests as either cellulitis or, more likely, single or multiple nontender erythematous nodule(s) at the site of traumatic inoculation. These nodules occasionally drain purulent material.
  • Lymphocutaneous nocardiosis manifests as similar lesions accompanied by ascending regional lymphadenopathy. The lymphadenopathy may also occasionally drain purulent material.
  • Nocardial species can cause mycetoma, a chronic, swollen, purulence-draining, subcutaneous infection of the extremities, typically encountered in tropical areas of the world.^[15]
• Postoperative wound infections due to Nocardia species are rare.
• Traumatic inoculation nocardial arthritis has occurred but is rare. This presents as a subacute or chronic monarthritis, typically involving the knee.
• Traumatic inoculation nocardial endophthalmitis has also occurred in rare instances.
• Pulmonary disease is the predominant clinical finding in most patients with nocardiosis.^{[8, 16]}

  • Pulmonary nocardiosis may be acute, subacute, or chronic.
  • Clinical manifestations include inflammatory endobronchial masses or localized or diffuse pneumonias, which may be accompanied by cavitation, abscess formation, pleural effusion, or empyema.
  • Symptoms in patients with nocardiosis are indistinguishable from those in patients with similar pulmonary infections of other microbial etiology. Cough with sputum production and fever are the dominant symptoms.
  • At least 40% of patients with disseminated nocardiosis have pulmonary infection; therefore, the clinical presentation may be dominated by the pulmonary symptoms.
• Patients with nocardiosis may present with deep abscess at any site, particularly in the lower extremities or the CNS. In patients with extra-CNS abscesses, fever and local symptoms predominate.

  • Up to 25% of nocardiosis cases (other than those involving mycetoma) involve the CNS. When occurring in isolation, CNS nocardiosis manifests as a slowly progressive mass lesion, with a host of specific neurologic findings related to the specific location of the abscess.
  • CNS nocardiosis is detected in 20-40% of disseminated nocardial infections. In two thirds of patients with CNS nocardiosis, clinical findings indicate abscess with or without meningitis, including fever, headache, stiff neck, and/or altered mental status.

The physical findings of nocardiosis also vary based on the site of infection.

• Patients with primary cutaneous nocardiosis present with cellulitis, cutaneous nodules, nodules with ascending lymphadenopathy, or with a mycetoma that is clinically indistinguishable from similar infections due to other pathogens.
• Patients with pulmonary nocardiosis present with findings of pulmonary consolidation with or without evidence of pleural effusions.
• The presentation of disseminated nocardiosis depends on the sites of infection.

  • Pulmonary findings frequently predominate.
  • Local findings associated with metastatic abscesses may be present at almost any site but are typically in the lower extremities. The combination of pneumonia and lower-extremity abscess is particularly suggestive of nocardiosis, although this is not seen exclusively in nocardiosis.
  • Patients with brain abscess may present with altered mental status, personality changes, or various localizing neurologic findings.
  • Patients with meningitis present with fever, altered consciousness, and meningismus.

Pulmonary and disseminated nocardiosis are clearly associated with immunocompromising conditions, with approximately 60% of cases of nocardiosis other than mycetoma occurring in individuals with some compromise of host defense systems. Conditions associated with an increased risk of pulmonary and disseminated nocardiosis include the following:

• Chronic pulmonary disease: Although pulmonary nocardiosis has been described in association with various chronic pulmonary diseases, patients with pulmonary alveolar proteinosis are at particular risk.
• Alcoholism
• Cirrhosis
• Lymphoreticular malignancy
• Solid-organ transplantation^[17]
• Bone marrow or stem cell transplantation
• Long-term corticosteroid use or Cushing syndrome
• Systemic lupus erythematosus
• Systemic vasculitis
• Ulcerative colitis
• Sarcoidosis
• Renal failure
• Whipple disease
• Hypogammaglobulinemia
• Treatment with anti–tumor necrosis factor antibody
• HIV infection and AIDS: Nocardiosis in individuals with advanced HIV disease usually presents as a relentlessly progressive infiltrative pulmonary infection. The median CD4 count in patients infected with HIV who develop nocardiosis is approximately 50 cells/µL.^[13]