II. Causes
- Common Causes
- Sporotrichosis: Sporothrix schenckii (fungus)
- Classic prototype of 'sporotrichoid' infection
- Gardening, splinters or Animal Bites or scratches
- Nocardia brasiliensis (Nocardiosis)
- Gardening or splinter exposure
- Mycobacterium marinum
- Aquariums, fish handling or other water exposure
- Leishmania brasiliensis (Leishmaniasis)
- Limited to sandfly endemic areas
- Sporotrichosis: Sporothrix schenckii (fungus)
- Other Causes
- Nocardia asteroides
- Atypical Mycobacteria
- Francisella tularensis
- Blastomyces dermatidis
- Coccidioides immitis
- Cryptococcus neoformans
- Histoplasma capsulatum
- Streptococcus Pyogenes
- Staphylococcus aureus
- Pseudomonas pseudomallei
- Bacillus anthracis (Anthrax)
- CowpoxVirus
III. Signs and Symptoms
- Exposure to soil or water borne organisms
- Granulomatous reaction up extremity lymph chain
- Nodular lesions
- Local tissue necrosis
- Abscess formation
- No systemic symptoms
IV. Differential Diagnosis
- See Subcutaneous Nodule (e.g. Rheumatoid Nodule)
- Cellulitis with ascending lymphangitis
