Microbiology · Dimorphic fungi
Sporothrix schenckii !
- Fungus
- Exam priority: medium
A fungus of plants and soil that enters through a thorn or splinter; it forms nodules that climb the arm along the lymphatic vessels.
Updated 2026-11-01
Also called: Sporothrix brasiliensis, rose gardener's disease, sporotrichosis
At a glance
- Shape
- In tissue, small oval or elongated cigar-shaped yeasts
- Family
- Ophiostomataceae (Ophiostomatales)
- Type
- Thermally dimorphic fungus: mold in the environment, yeast in tissue
- Stain
- PAS and silver (GMS) on biopsy; few yeasts are seen in tissue
- Size
- Yeasts of about 2–6 µm
Morphology
- In the environment: mold with conidia clustered like a flower at the tips of conidiophores
- In tissue: elongated, scarce yeasts
- Sometimes asteroid bodies: a yeast surrounded by radiating eosinophilic material
Transmission
- Skin inoculation by thorns (rose bushes), splinters, hay, moss or soil
- S. brasiliensis: scratches, bites or secretions of sick cats, mainly in Brazil
- Rarely by inhalation (lung form)
- Not spread from person to person
Reservoir: Soil, plants, moss, wood and hay; Cats (S. brasiliensis)
Isolation precautions
What the care team adds to standard precautions.
- Standard
Virulence factors
- Conversion to yeast in tissue
- Melanin and adhesins that aid survival
- Thermotolerance: strains that tolerate 37 °C can disseminate
Diseases it causes
- Sporotrichosis: lymphocutaneous form (most common), fixed cutaneous form and, in the immunosuppressed or people with alcohol use disorder, lung or disseminated disease Sporotrichosis and other subcutaneous mycoses →
Clinical picture
- A painless papule at the wound site that ulcerates
- New nodules in a line climbing the lymphatic path of the arm or leg
- Fixed cutaneous form: a plaque on the face or arm without a chain of nodules
- Disseminated: joints, bone and meninges in HIV
Diagnosis
- Culture of pus or biopsy: the reference method
- Biopsy with PAS or silver; yeasts are scarce
- PCR for the species
- Serology performs variably
Treatment
Itraconazole is the usual treatment for skin forms; alternatives are saturated solution of potassium iodide and terbinafine. Lung or disseminated forms need amphotericin B at first. Treatment lasts months.
Drug class only; doses and regimens are set by the clinician from the current guideline.
In Pharmacology:
Prevention
- Gloves and protective clothing when handling plants, moss, hay or soil
- Careful handling and veterinary care of cats with lesions
- Washing and watching thorn wounds
Test yourself
Think of the answer, then tap the question to see it.
Which lesion pattern is typical of lymphocutaneous sporotrichosis?
A lesion at the wound site followed by a line of nodules ascending along the lymphatic vessels.
Which animal transmits Sporothrix brasiliensis to people in South America?
The cat, through scratches, bites or lesion secretions.
What is the usual antifungal for cutaneous sporotrichosis?
Itraconazole; potassium iodide and terbinafine are alternatives.
Related
- Agents of chromoblastomycosis (Fonsecaea and other pigmented fungi)
- Dermatophytes (Trichophyton, Microsporum, Epidermophyton)
Related conditions
← Back to the group: Dimorphic fungi
Educational content on microorganisms; not a treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Sporotrichosis Basics (CDC, 2024); Clinical Overview of Sporotrichosis (CDC, 2024).
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Representative model, for educational purposes only.