Black molds are fungi that are found throughout our environment. When individuals with weakened immune systems come in contact with these fungi, they can develop life-threatening infections.


Black molds cause a wide variety of diseases. If these fungi get into breaks in the skin, they can form large warts or or cauliflower-like lesions in the skin. They can also cause areas of swelling and redness that may constantly leak fluid and be associated with pain and discomfort. Other molds may infect toenails or fingernails causing discoloration and strong>cracking.

Patients with defects in immunity (for example organ transplant patients receiving immunosuppressing agents to prevent rejection) may inhale these fungi and develop severe pneumonia. These molds can also become lodged in the air sinuses and cause sinusitis that fails to improve with antibiotic and decongestant therapy. In some cases infection can spread to the brain or even enter the blood stream resulting in spread throughout the body.


Infection of the skin and sinuses may require surgical excision. In some cases anti-fungal agents called azoles may help to control the infection.

There is no vaccine available and many infections do not respond well to our present therapies.


Black molds grow in moist warm soil. Florida’s tropical climate, with its heat and humidity, creates a perfect setting for fungi to grow and thrive. Increasing numbers of patients in Florida are receiving agents for arthritis, organ transplant and cancer treatment that suppress their immune systems. As ourvulnerable population increases, Florida is likely to suffer an explosive rise in the number of black mold infections.


It is very difficult to prevent exposure to this group of fungi because they are found throughout Florida’s environment. Patients with weakened immune systems should exercise great care to avoid skin injury. Good general health and hygiene help prevent these infections.

Prepared by:

M. Hong Nguyen, M.D.
Associate Professor of Medicine
University of Florida College of Medicine

Frederick Southwick, M.D.
Professor of Medicine and Chief of Infectious Diseases
University of Florida College of Medicine