II. Pathophysiology

  1. Filamentous gram-positive Bacteria
  2. Causes Nodular Lymphangitis
    1. Nocardia brasiliensis most common etiology

III. Exposure risks

  1. Soil or plant debris (e.g. gardening)
  2. Splinters

IV. Findings: Nocardiosis (80% of presentations)

  1. Respiratory infection (Pneumonia, Lung Abscess)
    1. Fever
    2. Cough
    3. Chest Pain
  2. CNS Infection (including Brain Abscess)
    1. Headache
    2. Seizures
    3. Confusion
    4. Lethargy
    5. Focal neurologic deficit
  3. Disseminated Nocardiosis
    1. Systemic symptoms and focal symptoms variable based on abscess location

V. Findings: Nodular Lymphangitis (20% of presentations are primary cutaneous or Lymphocutaneous Nocardiosis)

  1. Primary lesion follows one to six week incubation
    1. Tender nodular lesion develops at inoculation site
  2. Secondary lesions
    1. Erythematous Papules, Nodules develop up lymph chain
    2. Lesions ulcerate and drain purulent fluid
    3. Sinus tracts may form
  3. Other findings
    1. Fever
    2. Tender regional adenopathy occur

VII. Labs

  1. Microscopic examination
    1. Weakly Gram Positive Bacteria
    2. Filaments are acid-fast
  2. Culture (slow growth may require several weeks)
    1. Routine fluid culture
    2. Culture of biopsied tissue

VIII. Management

  1. Treatment Duration: 3 months (6 months if Immunocompromised)
  2. TMP-SMZ DS (Septra DS or Bactrim DS): preferred
    1. Dose: 5-10 mg/kg/day up to 2 DS tablets orally three times daily for three months
    2. Complete Blood Count weekly (lower dose if cytopenia)
  3. Alternative antibiotics (based on sensitivity)
    1. Minocycline 100-200 mg orally twice dailyfor three months
    2. Other antibiotics that have been used: Amikacin, Carbapenem antibiotics, Quinolone antibiotics, Linezolid

IX. Prognosis

  1. Mortality from Nocardiosis Pneumonia may be as high as 10% even in uncomplicated cases

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