Phaeohyphomycosis is a fungal infection that results in the formation of a cyst where the organisms can continue to breed. The term "phaeohyphomycosis" specifically refers to infections of fungi that are dark, with yeast-like cells or structures known as hyphae. A doctor can take a sample from the site of the infection for evaluation and culture in a lab to determine which organism is responsible and whether the issue is phaeohyphomycosis or another type of fungal infection.
This type of infection can develop when a patient inhales fungi or when spores are introduced as a result of trauma. For instance, the patient might pick up a splinter from a fencepost, and the splinter could drive fungal spores under the layers of the skin. Immunocompromised patients are more likely to develop phaeohyphomycosis, because their bodies cannot resist the development of a fungal colony. Patients who are mostly healthy might be able to fight the fungi off before they cause infection.
This condition commonly appears subcutaneously. The patient might experience symptoms such as itching and discomfort before a dark bloom starts to spread under the skin. It can be accompanied by swelling as a cyst begins to develop. The cyst typically has dark walls and might be flexible or pliable to the touch, if the patient can palpate it. A doctor can take a sample with a needle aspiration biopsy or scraping, if the fungi grow on the surface of the skin.
Rarely, phaeohyphomycosis can occur in the brain and central nervous system. The patient usually is extremely sick before inhaling fungi that manage to spread to the brain. In this case, the infection will not be immediately visible. The patient might develop cognitive deficits such as poor coordination, difficulty remembering things and attitude changes. A brain image can show a cyst inside the brain, and the patient might have elevated pressure inside the skull as a result of the infection.
The treatment of phaeohyphomycosis relies on a culture to determine what is causing the infection as well as an appropriate antifungal medication. The doctor might deliver a large loading dose to kill off as many fungi as possible. Some patients need supplemental medication to increase immune function or address complications. Surgery also might be a necessity in some cases, to excise the cyst. Patients who are in treatment for phaeohyphomycosis can discuss their options with a physician to decide on the best one for their needs, and they might want to consider aggressive treatment to prevent a systemic infection.