Sporotrichosis

Overview

Sporotrichosis/Rose Gardner's disease is a fungal infection caused by Sporothrix schenkii

Sporothrix schenckii is a thermally dimorphic fungus. This fungus is commonly found in soil and plant matter (Wood, Bark, Leaves).

Sporothrix schenkii has a tendency to spread along the lymphatics.

Cutaneous infection is the most common form of the infection. It occurs when the fungus enters the skin through a break in the skin like a small cut or scrape.

Types of Sporotrichosis

1. Cutaneous - The most common type of Sporotrichosis

2. Pulmonary - Caused by breathing in fungal spores

3. Disseminated - Occurs in people with lowered immunity

Risk Factors

People who touch plant matter are more likely to become infected. Sporotrichosis outbreaks have occurred among forest workers and people who work in tree nurseries and garden centers

Pathogenesis

Serine proteinase and Aspartic proteinase are the two proteinases produced by the fungus that help in local invasion

Clinical Features

Sporotrichosis is a chronic subcutaneous pyogranulomatous disease

1. Cutaneous form - 

Painless subcutaneous nodulo ulcerative lesion. Occurs along the lymphatics 

Lymph nodes become enlarged, indurated and has a cord like feeling on palpation

2. Pulmonary form - 

Cough, Chest pain, Dyspnoea, Fever

3. Disseminated form - 

Joint pain in case of joint involvement

Difficulty thinking, Headache, Seizures in case of CNS involvement

Diagnosis

1. KOH mount - Demonstrates elongated yeast cells

2. Histopathological staining - Demonstrates Asteroid bodies in biopsy specimens

Asteroid Body

A central basophilic yeast cell is surrounded by radiating extensions of eosinophilic mass composed of antigen antibody complexes. This eosinophilic halo is Splendore Hoeppli phenomenon.

3. Culture

S. schenkii is a dimorphic fungus

At 25*C - Produces mycelium form. Conidia are arranged in flower like pattern

At 37*C - Produces yeast form

Prevention

Sporotrichosis can be prevented by wearing protective clothing such as gloves and long sleeves when touching plant matter that can cause minor cuts or scrapes

Treatment

1. Cutaneous Sporotrichosis

Itraconazole - Taken orally - For 3 to 6 months

Supersaturated potassium iodide (SSKI) is an alternative treatment option for cutaneous sporotrichosis

2. Disseminated Sporotrichosis - Intravenous Amphotericin B

Surgery may be needed for Pulmonary Sporotrichosis