The species of fungus known as Cryptostroma corticale is generally isolated from trees, as it grows abundantly under the bark of maple trees as well as sycamore trees. The fungus also thrives in the barks of stored or stacked logs. Though it is usually found outdoors, this fungus is a major threat to humans, specifically loggers and other individuals who handle the aforementioned woods. This allergen causes more than just simple allergic reactions; it can lead to a health condition such as maple bark disease.

Maple bark disease is another name for hypersensitivity pneumonitis in loggers and sawmill workers. It is a hypersensitivity reaction to repeated inhalation of organic particles. Its symptoms may include fever, fatigue, chills and cough. Individuals like loggers and sawmill workers who inhale the spores of Cryptostroma corticale while working can suffer from these symptoms. Bark strippers are most susceptible to symptoms caused by Cryptostroma corticale.