Objective

2

To retrospectively analyze the symptoms and syndrome distribution characteristics of hypersensitivity pneumonitis （HP） patients and explore its etiology and pathogenesis.

Methods

2

The four diagnostic information of HP inpatients hospitalized at Beijing Hospital of Traditional Chinese Medicine between January 2016 and March 2024 was collected. The syndrome characteristics of HP patients were analyzed using the syndrome-element differentiation method.

Results

2

A total of 68 HP patients were included， with 16 nonfibrotic cases and 52 fibrotic cases. The most frequently occurring symptoms in the 68 patients were cough （94.1%）， expectoration （83.8%）， dyspnea （82.4%）， dry mouth （52.9%）， insomnia （38.2%）， poor appetite （29.4%）， and fatigue （25%）. Nonfibrotic HP patients predominantly exhibited cough （93.8%）， dyspnea （87.5%）， expectoration （81.3%）， dry mouth （50%）， fever （25%）， and fatigue （25%）， with higher incidences of fever， nasal congestion/sneezing/rhinorrhea， and wheezing. Fibrotic HP patients commonly presented with cough （94.2%）， expectoration （84.6%）， dyspnea （80.8%）， dry mouth （53.8%）， insomnia （44.2%）， poor appetite （34.6%）， chest tightness （25%）， and fatigue （25%）. Nonfibrotic HP can be discussed under "cough" and "dyspnea"， with the primary disease location in the lung or liver-lung systems. Pathological patterns are mostly excess syndromes， predominantly

yang

-related， often complicated by external pathogens. Excess syndromes include ascending of

qi

， stagnant heat， and fluid retention， while deficiency syndromes mainly present as

qi

deficiency. Fibrotic HP can be discusse

d under "lung impediment" and "lung atrophy"， with disease locations often involving multiple organs， most commonly the lung， lung-spleen system， lung-kidney system， or lung-spleen-kidney system. Pathological patterns are characterized by deficiency-excess complexity， with an emphasis on yin-related pathologies. Excess syndromes include phlegm-heat， stagnant heat， fluid retention， and blood stasis， while deficiency syndromes involve

qi

deficiency，

yin

depletion， and

yang

impairment.

Conclusion

2

HP patients exhibit complex and diverse clinical symptoms， with the primary disease location in the lungs. The pathogenesis reflects a root deficiency and manifest excess， with root deficiencies commonly related to the weakness of the lung， spleen， and kidney， while manifest excess is often associated with phlegm， fluid retention， stagnant heat， and blood stasis.