This patient apparently made a complete recovery from Löffler's pneumonia in 1957, but several months later began to have recurrent symptoms of wheezing and eosinophilia without further evidence of pulmonary infiltration. These occurrences were increasingly frequent during the ensuing four years, but they were always fairly mild. The persistent eosinophilia, the development of wheezing, the recurrent illnesses at closer and closer intervals, and finally the development of arthralgia, fever, neuritis, and vasculitis indicate that the original Löffler's pneumonia was related to the final fatal disease of periarteritis nodosa. This report indicates that Löffler's pneumonia is not invariably a bland disorder, but rather that it requires long-term follow-up, and possibly long-term treatment, in all cases.
Kinsella DL, Simpson HN. Löffler's Pneumonia Terminating in Fatal Periarteritis Nodosa. JAMA. 1967;202(9):867-869. doi:10.1001/jama.1967.03130220055008