Immunological aspects of infections part 47

As with viruses, there is a third possible outcome. If the fungal infection is not eliminated or causes persistent infection, then the host response may trigger a hypersensitivity reaction. As an example, Aspergillus fumigatus infections can persist  as an aspergilloma in preexisting lung cavities secondary to tuberculosis or bronchiectasis following childhood pertussis (whooping cough). Allergic bronchopulmonary aspergillosis may occur and is due to IgE-mediated hypersensitivity to the aspergillus antigens. Clinically, the condition presents as recurrent episodes of increased wheezing and coughing, fever and pleuritic pain similar to that seen in asthmatics. Another example is farmer's lung in which antigen-antibody complexes of Micropolyspora faeni cause a hypersensitivity reaction on the part of the host. The name farmer's lung indicates that this particular fungus is found in moldy hay.