Introduction: Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by immune-mediated inflammation and/or fibrosis after exposure to inhaled antigens. Advanced HP is associated with hypoxemic respiratory failure, reduced exercise tolerance, and impaired quality of life (QoL). High Flow Nasal Cannula (HFNC) therapy may improve dyspnoea and exercise capacity, facilitating participation in supervised domiciliary Pulmonary Rehabilitation (PR) programs. Clinical Case Description: A 61-year-old male (BMI 29.4 kg/m2) presented with dyspnoea, fatigue, and poor QoL (CAAT score: 24/40) in March 2025. Chest CT scan demonstrated a diffuse interstitial honeycombing pattern with bronchoalveolar lavage revealing 29% lymphocytosis, confirming fibrotic HP diagnosis, secondary to mold exposure. Patient was hospitalized a month later due to progressive dyspnoea and hypoxemic respiratory failure, despite long-term oxygen therapy at 5L/min at rest and 10L/min during ambulation. Systemic oral corticosteroid therapy was initiated. After this hospitalization, patient started a domiciliary PR program, which included breathing techniques (ACBT and Aerobika® OPEP device), patient education and continuous treadmill-based endurance training. A second hospitalization occurred in August 2025 due to clinical deterioration and hypoxemia worsening, leading to start HFNC therapy (Tivan®LS; Linde), prescribed for 4-6 hours/ day, with a flow rate of 30 L/min and oxygen supplementation up to 12 L/min (FiO2~50%) during aerobic training. Antifibrotic therapy with nintedanib and after mycophenolate mofetil (steroid-sparing) were also initiated. Following discharge, patient continued a domiciliary HNFC-supported PR program, with telemonitoring and self-reported training data via Telehealth centre from ULS São José. After 8-months, there was a reduction in dyspnoea, an increase in exercise capacity, QoL and functional status. No further exacerbations or hospitalizations were reported during the 4-month follow-up period, and the patient awaits lung transplant. Conclusions: This case highlights PR as a cornerstone intervention in advanced fibrotic HP, with HFNC support as a safe and helpful domiciliary solution contributing to improved functional outcomes and symptom management.
Pérez et al. (Wed,) studied this question.