Sporotrichosis


Sporotrichosis is a disease caused by the infection of the fungus Sporothrix schenckii. This fungal disease usually affects the skin, although other rare forms can affect the lungs, joints, bones, and even the brain. Because roses can spread the disease, it is one of a few diseases referred to as rose-thorn or rose-gardeners' disease. The species was named for Benjamin Schenck, a medical student who in 1896 was the first to isolate it from a human specimen.
Because S. schenckii is naturally found in soil, hay, sphagnum moss, and plants, it usually affects farmers, gardeners, and agricultural workers. It enters through small cuts and abrasions in the skin to cause the infection. In case of sporotrichosis affecting the lungs, the fungal spores enter through the respiratory pathways. Sporotrichosis can also be acquired from handling cats with the disease; it is an occupational hazard for veterinarians.
Sporotrichosis progresses slowly – the first symptoms may appear 1 to 12 weeks after the initial exposure to the fungus. Serious complications can also develop in patients who have a compromised immune system.

Signs and symptoms

Cutaneous lesions can become superinfected with bacteria, resulting in cellulitis.

Diagnosis

Sporotrichosis is a chronic disease with slow progression and often subtle symptoms. It is difficult to diagnose, as many other diseases share similar symptoms and therefore must be ruled out.
Patients with sporotrichosis will have antibody against the fungus S. schenckii, however, due to variability in sensitivity and specificity, it may not be a reliable diagnosis for this disease. The confirming diagnosis remains culturing the fungus from the skin, sputum, synovial fluid, and cerebrospinal fluid. Smears should be taken from the draining tracts and ulcers.
Cats with sporotrichosis are unique in that the exudate from their lesions may contain numerous organisms. This makes cytological evaluation of exudate a valuable diagnostic tool in this species. Exudate is pyogranulomatous and phagocytic cells may be packed with yeast forms. These are variable in size, but many are cigar-shaped.

Prevention

The majority of sporotrichosis cases occur when the fungus is introduced through a cut or puncture in the skin while handling vegetation containing the fungal spores. Prevention of this disease includes wearing long sleeves and gloves while working with soil, hay bales, rose bushes, pine seedlings, and sphagnum moss. Also, keeping cats indoors is a preventative measure.

Treatment

Treatment of sporotrichosis depends on the severity and location of the disease. The following are treatment options for this condition:
Sporotrichosis can be diagnosed in domestic and wild mammals. In veterinary medicine it is most frequently seen in cats and horses. Cats have a particularly severe form of cutaneous sporotrichosis and also can serve as a source of zoonotic infection to persons who handle them and are exposed to exudate from skin lesions.