Abstract Introduction Hypersensitivity pneumonitis (HP) is an interstitial lung disease where lung parenchyma has an immunologic reaction to an inhaled allergen. Variable clinical presentation and severity of this disease pose diagnostic challenges. Here we present a young adult with suspected hypersensitivity pneumonitis. Description A 17-year-old recent immigrant from Brazil presented to a children’s hospital with subacute, worsening cough, and chest and epigastric pain. She was admitted to the PICU for hypoxic respiratory failure requiring BiPAP. A CT chest on admission showed bilateral ground glass nodular opacities. She underwent an extensive infectious and non-infectious workup including bronchoscopy. Her BAL showed a lymphocytic predominance (52%). Her labs showed a positive urine histoplasma (though negative on serum and BAL), negative Karius, with BAL positive for acid fast bacilli (tuberculosis testing negative). She was treated with multiple antimicrobials with improvement. Ultimately, it was felt that her infectious markers were false positives despite improvement on antibiotics. She rapidly improved and was discharged home. A pneumonitis panel resulted after her discharged, which was positive for: Aspergillus antibody, Micropolyspora, and pigeon antibody. Despite improvement, she was admitted again four days later for respiratory failure. Given prior negative infectious work up, the patient was started on steroids for concern of HP, with rapid improvement in her oxygenation status. She was discharged on a prolonged steroid taper but had relapsing episodes of respiratory failure when tapered, requiring multiple admissions and re-dosing of steroids. It is unclear what her initial trigger was. Upon further review, she had several exposure risks, including poultry and cats, prior to her immigration. There were also reports of potential mold exposure. She remains on low level steroids and inhaled triple inhaler with improvement in her symptoms. Discussion Hypersensitivity pneumonitis is often a diagnosis of exclusion, owing to its overlap with infection, edema and other interstitial lung diseases. In 60% of cases, no trigger is found. Patients typically improve with steroids and removal of the atopic trigger. Our patient’s positive infectious labs were ultimately thought to be false positives which delayed her diagnosis. Clinicians should maintain a high index of suspicion for HP, as timely recognition can significantly influence management. This abstract is funded by: None
Muniz et al. (Fri,) studied this question.