“…It is likely, however, that Penicillium frequentans has an important role, since in one patient, it was the only fungus testing positive in the skin prick test, specific IgG determination, and SIC. In addition to being the reference standard for the diagnosis of HP, (10,(21)(22), SIC also enables identification of the causative agent. With the use of this test, it has been established that in certain types of HP, various agents can be the cause in different individuals, and, although it is less common, different agents can be implicated in the same patient (20).…”