The Definitive Diagnostic Process and Successful Treatment for ABPM Caused by Schizophyllum commune: A Report of Two Cases

ABSTRACTBackground: Although mucoid impaction of the bronchi (MIB) is a well-known manifestation in allergic bronchopulmonary mycosis (ABPM), when unknown samples or plural eumycetes are cultured from bronchial materials, several problems are encountered which can affect the definitive diagnostic process or successful treatment.Case Summary: The definitive diagnostic process of two patients [a 58-(Case 1) and a 70-(Case 2) year-old female] with MIB was: 1) to identify the existence of any allergic respiratory disorder, 2) to detect the fungi obtained from bronchial materials, with use of the 28S rDNA sequencing and analysis, 3) to investigate whether the detected fungus was a probable etiologic antigen, and 4) to make the final diagnosis based on the results of the inhalation examinations using the antigenic solution of the fungi. As a treatment strategy, bronchial toilet and low dose itraconazole therapy were planned according to the clinical manifestations of each patient.Discussion: The two patients with MIB were successfully diagnosed as ABPM caused by Schizophyllum commune (Sc-ABPM) accompanied with hyperattenuating mucoid impaction. The reliability of some allergological makers as a substitution for the bronchoprovocation test should be clarified in near future. Clinical manifestations demonstrated in our cases suggested that the allergic reaction such as eosinophilic bronchoalveolitis spreading around the mucus plug was a primary lesion underlying the Sc-ABPM. The success of the treatment for Sc-ABPM will be achieved by the strategy targeting to fundamental condition and by the control of the disease recurrence by means of effective environmental management.