Abstract Hypersensitivity pneumonitis (HP) is an immune-mediated disease that manifests as interstitial lung disease after exposure to certain factors. Classification into acute, subacute, and chronic types is based on acuity, length of exposure and presence of fibrotic changes on imaging. Lack of established guidelines for diagnosis makes it a challenging disease. Confident diagnosis of HP generally requires high resolution computerized tomography (HRCT) and bronchoalveolar lavage. Of many different presentations of HP, bilateral pneumothorax appears to be of rare finding. Here we present a case of asymptomatic spontaneous bilateral pneumothoraces in the setting of chronic HP from exposure to birds. A previously healthy 59 year old female presented with one year of exertional dyspnea and weight loss. Chest x-ray suggested pulmonary fibrosis. HRCT revealed extensive fibrosis, traction bronchiectasis, and basilar honeycombing with bilateral pneumothoraces. The patient was instructed to go to the emergency department, where a left-sided pigtail chest tube was inserted.She remained stable but was admitted for chest tube management. Further investigation revealed she had 2 parrots since 2 years prior with two cockatiels in the past 5 months. Infectious workup including HIV, Quantiferon, Fungitell, coccidioidomycosis antibodies, blood and pleural fluid cultures were negative. Autoimmune panel, angiotensin converting enzyme. alpha-1 antitrypsin, complements were negative as well. Pleural studies showed lymphocytic predominant exudative fluid with mixed inflammatory cells on cytology. The right pneumothorax continued to increase in size, resulting in chest tube insertion. Repeat CT chest showed nonspecific interstitial pneumonia (NSIP) pattern with incomplete pleural apposition bilaterally. Bronchoscopy with lavage and transbronchial cryobiopsy was performed. High dose steroid taper was started to mitigate any ongoing inflammation. Both chest tubes were eventually removed when pneumothoraces persisted after clamping. The patient remained asymptomatic on room air throughout hospitalization, thus planned pleurodesis was deferred. Final pathology shows chronic fibrosing interstitial pneumonia such as chronic hypersensitivity pneumonitis, connective tissue disorder, or idiopathic. Lavage fluid showed CD4:CD8 ratio 32 and fungal culture came back as Aspergillus niger. HP can be difficult to diagnose given various levels of acuity and lack of universal guidelines. Chronic HP results from prolonged low-level of antigen exposure, from mold, bird feathers, or animal dander. Onset is gradual, as in our patient, which led to delayed recognition. The rare presentation of bilateral spontaneous pneumothorax and underlying parenchymal disease is being managed conservatively due to subtle symptoms. Other treatment considerations include initiation of anti-fibrotic agents and lung transplant evaluation. This abstract is funded by: none
Eom et al. (Fri,) studied this question.