II. Definitions

  1. Mycetoma (Maduramycosis)
    1. Chronic progressive subcutaneous, Granulomatous infection
    2. Caused by non-acid fast Bacteria (Actinomycetoma) and fungi (Eumycetoma)
    3. Subcutaneous Nodules, abscesses, fistulae and swelling, typically on legs, and may involve hands
    4. Complications include local disfiguring lesions, and if untreated, Osteomyelitis or ankylosis
    5. Rare, life threatening systemic spread to Pelvis, lungs, spinal cord
  2. Actinomycetoma
    1. Chronic subcutaneous, Granulomatous lesions due to Actinomycetes, non-acid fast Bacteria
    2. Actinomycetes include soil-based Bacteria, Actinomadura, Nocardia, Streptomyces
  3. Eumycetoma
    1. Chronic subcutaneous, Granulomatous lesions due to fungal infection

III. Causes: Nodular Lymphangitis

  1. Common Causes
    1. Sporotrichosis: Sporothrix schenckii (fungus)
      1. Classic prototype of 'sporotrichoid' infection
      2. Gardening, splinters or Animal Bites or scratches
    2. Nocardia brasiliensis (Nocardiosis)
      1. Gardening or splinter exposure
    3. Mycobacterium marinum
      1. Aquariums, fish handling or other water exposure
    4. Leishmania brasiliensis (Leishmaniasis)
      1. Limited to sandfly endemic areas
  2. Other Causes
    1. Nocardia asteroides
    2. Atypical Mycobacteria
    3. Francisella tularensis
    4. Blastomyces dermatidis
    5. Coccidioides immitis
    6. Cryptococcus neoformans
    7. Histoplasma capsulatum
    8. Streptococcus Pyogenes
    9. Staphylococcus aureus
    10. Pseudomonas pseudomallei
    11. Bacillus anthracis (Anthrax)
    12. CowpoxVirus

IV. Findings: Nodular Lymphangitis

  1. Exposure to soil or water borne organisms
  2. Granulomatous reaction up extremity lymph chain
    1. Nodular lesions
    2. Local tissue necrosis
    3. Abscess formation
  3. No systemic symptoms

V. Labs: Histology

  1. Mycetoma
    1. Suppurative Granulomas
    2. Neutrophil infiltrates
    3. Palisaded histiocytes
  2. Actinomycetoma
    1. Thin filaments (0.5 to 1 um) on Gram Stain or methenamine silver stain
  3. Eumycetoma
    1. Thick fungal hyphae

VI. Differential Diagnosis

  1. See Subcutaneous Nodule (e.g. Rheumatoid Nodule)
  2. Cellulitis with ascending lymphangitis

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