Fungal chitin is not an independent mediator of allergic fungal asthma severity.

Chitin, a polysaccharide found in the fungal cell wall and the exoskeletons of house dust mites and cockroaches, has garnered attention as a potential immunoreactive allergen. Mammals have evolved to express chitin-degrading chitinases (acidic mammalian chitinase/AMCase and chitotriosidase) that may modulate immune responses to chitin. We have previously reported that mice deficient in AMCase () demonstrated better lung function during allergic fungal asthma.

Hematopoietic 12/15-lipoxygenase activity negatively contributes to fungal-associated allergic asthma.

Asthma is one of the most common noncommunicable diseases in the world. Approximately 30% of severe cases are associated with fungal sensitization, often associated with allergy to the opportunistic mold . Leukotrienes, immunopathogenic mediators derived from the metabolism of arachidonic acid (AA) by 5-lipoxygenase (5-LOX), are often elevated in severe asthma.