Sporotrichosis is infection caused by the fungus Sporothrix schenckii.
The infection develops when the fungi enter the body through small cuts and scrapes in the skin.
Usually, the skin and nearby lymph nodes are infected, resulting in bumps on the skin and swollen lymph nodes.
Rarely, the lungs, joints, or other parts of the body are infected.
Diagnosis requires culture and identification of the fungus in a sample of infected tissue.
Itraconazole is used to treat most infections, but amphotericin B is required for bodywide infections.
Sporothrix fungi typically grow on rosebushes, barberry bushes, sphagnum moss, and other mulches. In contrast to many other fungal infections, Sporothrix fungi enter the body through small cuts and scrapes in the skin. Most often, farmers, gardeners, horticulturists, and timber workers are infected.
Sporotrichosis affects mainly the skin and nearby lymphatic vessels. Very rarely, bones, joints, lungs, or other tissues are infected.
An infection of the skin typically starts on a finger or hand as a small, nontender bump (nodule) that slowly enlarges and forms a open sore. Over the next several days or weeks, the infection spreads through the lymphatic vessels of the finger, hand, and arm to the lymph nodes, forming more nodules and open sores along the way. Pus from the lymph nodes may break through the skin, causing an opening that infected material drains through. Even at this stage, there is little or no pain. Usually, people have no other symptoms. This infection is seldom fatal.
Other symptoms are rare. An infection in the lungs may cause pneumonia, with a slight chest pain and cough. Lung infection usually occurs in people who have another lung disorder, such as emphysema.
Joint infection causes swelling and makes movement painful.
Very rarely, sporotrichosis spreads throughout the body. Such infections are life threatening and are more common among people with a weakened immune system.
Skin infections are treated with itraconazole given by mouth.
If the infection is severe, amphotericin B is given intravenously.
After the infection is controlled, people with AIDS or another condition that weakens the immune system may need to take itraconazole by mouth until their immune system has recovered, possibly for the rest of their life. Itraconazole helps prevent sporotrichosis from recurring while the immune system is weak.