Sporotrichosis is infection caused by the fungus Sporothrix schenckii.
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 a puncture wound to the skin. Most often, farmers, gardeners, and horticulturists are infected.
Sporotrichosis affects mainly the skin and nearby lymphatic vessels. Very rarely, bones, joints, lungs, or other tissues are infected.
Symptoms and Diagnosis
An infection of the skin typically starts on a finger as a small, nontender bump (nodule) that slowly enlarges and forms a 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 nodules and sores along the way. Even at this stage, there is little or no pain. Usually, people have no other symptoms. This infection is seldom fatal.
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. Rarely, an infection develops in other areas and can spread throughout the body. Such infections are life threatening.
The characteristic nodules and sores may lead a doctor to suspect sporotrichosis. The diagnosis is confirmed by growing (culturing) and identifying Sporothrix in samples of infected tissue.
Skin infections are treated with itraconazole given by mouth. Potassium iodide, given by mouth, may be prescribed instead, but it is not as effective and, in most people, has side effects (such as a rash, a runny nose, and inflammation of the eyes, mouth, and throat).
Lung and bone infections may also be treated with itraconazole. For bodywide infections, amphotericin B is given intravenously.
Last full review/revision October 2008 by Alan M. Sugar, MD