Sporotrichosis is a rare infection which is caused by a fungus known as sporothrix. This fungus lives throughout the world in soil and on plant matter like sphagnum moss, rose bushes, and hay. One can suffer from sporotrichosis by just coming in contact with the fungal spores in the environment.
Cutaneous (skin) infection is the most common form of the infection. It happens when the fungus enters the skin through a small cut or scrape, usually after handling contaminated plant matter. Most cases of sporotrichosis have been linked with scratches or bites from animals, particularly cats.
Types of sporotrichosis
How is sporotrichosis diagnosed?
- Cutaneous sporotrichosis is the most common form of the infection. It usually happens on a person’s hand or the arm after they have been handling contaminated plant matter.
- Pulmonary (lung) sporotrichosis is very rare condition but can happen after someone breathes in fungal spores from the environment.
- Disseminated sporotrichosis happens when the infection spreads to another part of the body, like the bones, joints, or the central nervous system. This form of sporotrichosis generally affects people who have weakened immune systems, like people with HIV infection.
Sporotrichosis is typically diagnosed when your doctor takes a small tissue sample (biopsy) of the infected area of the body. The sample is sent to laboratory for tests to find out what is causing the infection. Blood tests can help diagnose severe sporotrichosis, but they often can’t diagnose a cutaneous infection.
Symptoms of sporotrichosis
The symptoms of sporotrichosis rely on where the fungus is growing. Contact your doctor if you have symptoms that you think are related to sporotrichosis.
Sporotrichosis usually affects the skin or tissues underneath the skin. Usually the first symptom of cutaneous sporotrichosis is small, painless bump that can be developed at any time from 1 to 12 weeks after exposure to the fungus.
The bump can be red, pink, or purple, and it usually appears on the finger, hand, or arm where the fungus has entered through a break in the skin.
The bump will eventually grow larger and may look like an open sore or ulcer that is very slow to heal. Additional bumps or sores may appear later near the original one.
Pulmonary (lung) sporotrichosis is less commonly occurred than the cutaneous form of the infection. Some of the symptoms of pulmonary sporotrichosis include cough, shortness of breath, chest pain, and fever.
Symptoms of disseminated sporotrichosis basicdepend on the body part affected. For example, infection of the joints can cause joint pain that may be confused with rheumatoid arthritis. Infections of the central nervous system can involve difficulty thinking, headache, and seizures.
How is sporotrichosis treated?
Most cases of sporotrichosis only involve the skin or the tissues underneath the skin. It must be treated with prescription antifungal medication for several months and these infections are not life threatening. The most common treatment for this type of sporotrichosis is itraconazole, taken by mouth for 3 to 6 months.
Supersaturated potassium iodide (SSKI) is another treatment option that is available for cutaneous (skin) sporotrichosis. However, SSKI and azole drugs such as itraconazole should not be used at the time of pregnancy.
Patients who are suffering with severe forms of sporotrichosis are usually treated with amphotericin B, which is given through a vein. Often itraconazole is used after the initial treatment with amphotericin B, for a total of at least 1 year of antifungal treatment. People suffering with sporotrichosis in the lungs may also need surgery to cut away the infected tissue.