Household Mold as a Significant Cause of Hypersensitivity Pneumonitis

Recent research indicates that indoor mold exposure is a notable contributor to hypersensitivity pneumonitis (HP), a severe immune-mediated lung condition. A study conducted by investigators at the University of Texas Southwestern Medical Center revealed that approximately 25% of cases in their interstitial lung disease registry could be traced back to mold exposure within patients' homes. Mold thrives in environments with persistent moisture, such as after flooding, heavy rains, or leaks from pipes and roofs. It colonizes areas like bathrooms, bedrooms, and HVAC systems, particularly when ventilation is inadequate.

This study analyzed records from 231 patients diagnosed with hypersensitivity pneumonitis between 2011 and 2019. Of these, 54 patients demonstrated confirmed mold exposure in their homes, often linked to chronic leaks. Diagnosis relied on multidisciplinary assessments, including imaging, biopsies, and detailed environmental histories. Invasive testing supported the presence of mold in about 86% of cases, with diagnosis confirmed when contaminated materials were removed or leaks repaired.

Patients who eliminated mold exposure showed notable improvement, with around 12.2% experiencing increased lung capacity within months and none experiencing deterioration. Those with fibrotic disease also benefited, indicating that environmental intervention can positively influence disease progression and outcomes. The findings suggest that household mold is an under-recognized modifiable factor in hypersensitivity pneumonitis, prompting clinicians to consider detailed environmental exposure assessments routinely.

With climate change potentially increasing mold growth due to more frequent flooding and heat, public health and medical communities are urged to raise awareness. Addressing indoor mold may reduce the burden of hypersensitivity pneumonitis and improve patient prognosis.

Source: https://medicalxpress.com/news/2025-05-household-mold-linked-hypersensitivity-pneumonitis.html