Nodules can be 2 to 4 cm, and appear along the lymphatics, typically in the arms and legs (and face, in children)
They become indurated, then ulcerated
May have regional lymphadenopathy
Usually mild or no systemic symptoms
Fixed cutaneous
Only a single lesion, fixed at the point of inoculation
Lesions may be papular, plaques, nodular, verrucous, or ulcerated
Disseminated or multifocal
Only occurs in patients with immunodeficiency, including alcoholism, diabetes, sarcoidosis, tuberculosis, transplantation, malignancy, immunosuppressive medication, or advanced HIV
Can be in the context of HIV IRIS
Lesions can include ulcerations, aceniform, plaques, or crusts
Worst prognosis is with dissemination to lungs or meninges
Extracutaneous
Rare presentation without skin lesions, caused either by inhalation or deep inoculation
Musculoskeletal infections are the most common, with septic arthritis followed by osteomyelitis or tenosynovitis
Pulmonary sporotrichosis is more common in men aged 30 to 60 years, and presents similarly to pulmonary tuberculosis
Major risk factors: alcohol (1/3); sarcoidosis, TB, or diabetes (1/3); otherwise healthy (1/3)
Sporotrichotic meningitis is rare and occurs in immunocompromised patients
Can also affect eyes, genitals, or oropharyngeal mucosa
Punch biopsy, can be with sterile saline if needed (not in formalin)
Direct microscopy
May see yeast forms or characteristic asteroid bodies (especially from deep swabs)
Culture
Sab + chloramphenicol at 25ºC for 5 to 7 days for mold form followed by BHI at 35-37ºC for 5 to 7 days for yeast form
Colony appearance is a white mold that becomes dark
Molecular tests
Some labs have developed PCR diagnostics
Serology
Tube or latex agglutination have specificity (95%) and sensitivity (98-100%)
Immunoassays also exist
Sporotrichin skin test
Essentially like a TB skin test but for sporotrichosis
Only useful for epidemiologic surveys
Management
First-line: itraconazole 100 to 200 mg po daily until 2 to 4 weeks after the lesions resolve (around 3 to 6 months)
Dose may be increased to 400 mg if there's a poor response, there are extracutaneous infections including osteoarticular or pulmonary disease, or the host is immunocompromised
For severe pulmonary infection, use amphotericin B 3 to 5 mg/kg daily (liposomal), stepped down to itraconazole 200 mg po bid when better, to complete at least 12 months total
Same treatment for disseminated disease
For meningeal infection, use amphotericin B 5 mg/kg daily for 4 to 6 weeks, followed by itraconazole 200 mg po bid until at least 12 months
For children, use itraconazole 6 to 10 mg/kg (max 400 mg) daily
For severe disease in children, use amphotericin B 0.7 mg/kg daily induction then itraconazole 6 to 10 mg/kg (max 400 mg) daily
Potassium iodide
Used more outside of developed countries, since it is cheap
Poorly tolerated, though, with numerous side effects
