Allergic bronchopulmonary mycosis due to Schizophyllum commune in a patient with chronic hepatitis B.

INTRODUCTION: Schizophyllum commune (S. commune) is an opportunistic pathogenic fungus and can cause infection of the respiratory system in immunocompromised hosts. Allergic bronchopulmonary mycosis (ABPM) is the major disease caused by S. commune. However, identification of S. commune using routine mycological diagnostic methods is difficult. It is easy to make mistakes in diagnosis and treatment, resulting in deterioration of the disease. We report the first case of ABPM due to S. commune in a Chinese patient with chronic hepatitis B.

CASE PRESENTATION: The patient presented cough, sputum and dyspnea for six months. The pathogen was missed during routine laboratory workup. We performed bronchoscopy examination and bronchoalveolar lavage. S. commune was identified by metagenomic next-generation sequencing (mNGS) of bronchial alveolar lavage fluid (BALF). Hence, the patient was immediately treated with 200 mg voriconazole twice daily (intravenous infusion) and 20 mg prednisone once a day (oral therapy), along with oral entecavir for hepatitis B. There was no recurrence of infection after the medication was discontinued.

CONCLUSIONS: S. commune infection should be considered in the diagnosis of patients with refractory cough, sputum and dyspnea, especially in immunocompromised individuals. The mNGS technique is an effective supplementary technique for the diagnosis of S. commune infection, enabling precise clinical decision-making and appropriate treatment. Most patients have good prognosis with a combination of proper antifungal therapy and hormonal therapy.