How is sporotrichosis diagnosed and treated?

From the Guidelines

Sporotrichosis is diagnosed through a combination of clinical evaluation, fungal cultures, and sometimes histopathology, with treatment primarily involving antifungal medications, such as itraconazole, which is the first-line therapy. The diagnosis of sporotrichosis involves a healthcare provider examining the skin lesions and taking a medical history, then collecting a sample from the infected area for laboratory testing. The definitive diagnosis comes from culturing the fungus Sporothrix from tissue samples, skin scrapings, or pus, which typically takes 1-2 weeks to grow, as recommended by the global guideline for the diagnosis and management of the endemic mycoses 1.

Diagnosis and Treatment

• The diagnosis is based on culturing the fungus Sporothrix from tissue samples, skin scrapings, or pus.
• Treatment primarily involves antifungal medications, with itraconazole being the first-line therapy.
• For cutaneous or lymphocutaneous sporotrichosis, itraconazole 200 mg daily is typically prescribed for 3-6 months, continuing for 2-4 weeks after lesions resolve, as per the guidelines 1.
• For severe or disseminated infections, amphotericin B may be used initially (0.7-1.0 mg/kg/day), followed by itraconazole.
• Terbinafine (500 mg twice daily) can serve as an alternative when itraconazole cannot be used, as suggested by the clinical practice guidelines for the management of sporotrichosis 1.
• Fluconazole is less effective but may be considered in certain situations, although it is not the preferred treatment option 1.

Additional Considerations

• Local heat therapy can supplement medication for cutaneous forms since Sporothrix is sensitive to higher temperatures.
• Treatment duration varies based on infection severity and patient response, with regular monitoring of liver function recommended during antifungal therapy due to potential hepatotoxicity, as emphasized in the practice guidelines for the management of patients with sporotrichosis 1.
• The choice of treatment depends on the severity of the infection and the patient's overall health, with the most recent guidelines providing a comprehensive approach to managing sporotrichosis 1.

From the FDA Drug Label

Amphotericin B for Injection USP is specifically intended to treat potentially life-threatening fungal infections: aspergillosis, cryptococcosis (torulosis), North American blastomycosis, systemic candidiasis, coccidioido-mycosis, histoplasmosis, zygomycosis including mucormycosis due to susceptible species of the genera Absidia, Mucor and Rhizopus, and infections due to related susceptible species of Conidiobolus and Basidiobolus, and sporotrichosis. Sporothrix schenckii, are all inhibited by concentrations of amphotericin B ranging from 0.03 to 1. 0 mcg/mL in vitro.

The diagnosis of sporotrichosis is not directly addressed in the provided drug labels. However, the treatment of sporotrichosis with amphotericin B is mentioned, indicating that it is a potentially life-threatening fungal infection that can be treated with this medication.

• The provided drug labels do not contain information on how sporotrichosis is diagnosed.
• Sporotrichosis can be treated with amphotericin B, as stated in the drug labels 2.
• The dosage and administration of amphotericin B for sporotrichosis are described in the drug label 2, with therapy ranging up to nine months with a total dose up to 2.5 g.

From the Research

Diagnosis of Sporotrichosis

• The diagnosis of sporotrichosis is suggested by biopsy specimen and confirmed by tissue culture 3
• Molecular diagnostic tests, such as multiplex real-time PCR, are rapid and have high sensitivity and standardized operating processes 4
• A novel multiplex real-time PCR method based on the calmodulin (CAL) gene can be used for the identification of clinically relevant Sporothrix species: S. globosa, S. schenckii s. str., and S. brasiliensis 4
• The sensitivity and specificity of the multiplex real-time PCR assay reached 100%, with limits of detection (LODs) of 10 copies, 10 copies and 100 copies for S. globosa, S. schenckii s. str and S. brasiliensis, respectively 4

Treatment of Sporotrichosis

• Itraconazole is considered the treatment of choice for sporotrichosis 5, 6, 3
• Potassium iodide is still used in some undeveloped countries due to its safety and low cost 7, 6, 3
• Terbinafine has been observed to be effective in the treatment of cutaneous sporotrichosis 7, 6
• Amphotericin B is used initially for the treatment of severe, systemic disease, during pregnancy and in immunosuppressed patients until recovery, then followed by itraconazole for the rest of the therapy 6, 3
• The therapeutic response to itraconazole is excellent with the minimum dose, and there is a low incidence of adverse events and treatment failure 5