Fungus – Mucormycosis

October 31st, 2010

Mucormycosis is a fungal infection in the Zygomyces class that I occasionally encounter in my The Woodlands dermatology and Conroe dermatology offices.  It is most commonly seen in immunocompromised patients, especially diabetics who are ketoacidotic (very poorly controlled).  Additionally, patients with leukemia, lymphoma, AIDS, severe burns, and malnourishment are also susceptible.  There are five major types of Mucormycosis: Rhinocerebral (Nose and Central Nervous System), Pulmonary, Cutaneous, Gastrointestinal, and Disseminated.  A common feature of all five types is that the fungus invades the blood vessels producing infarction leading to gangrene and necrosis.  On the skin, the infarction appears as black eschars which can become infected leading to cellulitis and abscesses.  The skin can become infected with Mucormycosis through dissemination from an internal organ system or from direct inoculation from trauma.  The fungi causing Mucormycosis are found in our natural environment such as the soil, plants, animals and can be airborne.  The three most common genuses causing Mucormycosis are Rhizopus, Absidia, and Mucor.  Diagnosis of Mucormycosis is through fungal culture or skin biopsy.  On skin biopsy, the fungal hyphae are very characteristic with thick walls and a hollow appearance on cross section that appears like a large drinking straw.  Treatment of Mucormycosis involves excision of the affected areas as well as systemic antifungals such as Amphotericin B.