Long-term Physiologic Outcome after Acute Farmer's Lung

doi:10.1378/chest.87.6.796

Chest

Volume 87, Issue 6, June 1985, Pages 796-800

https://doi.org/10.1378/chest.87.6.796 Get rights and content

We performed a follow-up study of 61 patients who had an acute episode of farmer's lung (54 men and seven women). Twenty-four subjects had ceased all contact with the barn, while 37 had continued farming. Pulmonary function tests for all subjects showed an initial improvement after the acute episode: 92.4 ± 36.9 percent of predicted for carbon monoxide diffusing capacity (Dco) after one year, compared to 61.5 ± 28.5 percent at diagnosis (p<0.01); and 6.01 ± 1.50 L for total lung capacity (TLC) after three years, compared to 5.35 ± 1.42 L (p<0.05). Subsequently, pulmonary function decreased over time. Five years or more after the acute episode, pulmonary function tests in subjects who had continued farm work were not worse than those of subjects who had ceased contact for Dco (68.1 ±21.4 percent of predicted vs 80.6 ± 27.7 percent, respectively [p>0.1]) and for TLC (5.55 ± 1.31 L vs 5.90±0.84 L [p>0.2]). Ibis study shows that during a long-term follow-up, subjects with farmer's lung who stayed on the farm have subnormal values for pulmonary function but comparable values to those who left their farm.

Section snippets

Materials and Methods

The population under study consisted of 61 proven cases of farmer's lung. There were 54 men and seven women, with a mean age of 39 years (range, 13 to 71 years). Diagnosis was based on a combination of factors, including known exposure, typical clinical presentation, physical examination, chest roentgenograms, pulmonary function tests, serum precipitins, bronchoalveolar lavage, transbronchial lung biopsy, trephine lung biopsy, and, when doubt still persisted, open lung biopsy. Serum analysis

Results

The number of subjects tested at each time interval varied from 57 at diagnosis to ten at nine or more years after diagnosis. The parameter that showed the greatest change between the acute episode and one year after was Dco (61.5 ± 28.5 percent of predicted vs 92.4 ± 36.9 percent of predicted; n = 11 subjects; p<0.01; Fig 1); Dco was also higher than at diagnosis for the intervals of three to four years and five to six years (p<0.05), but not for the intervals of two years, seven to eight

Discussion

Our data show that after an episode of acute farmer's lung, most farmers do not progress to disabling pulmonary fibrosis even if they stay on their farm. Eventual loss of pulmonary function seems to result more from the initial attack than from continued exposure. Only the outcome of Dco was related to continuous contact with the offending allergen. These results agree with previously reported studies.8, 9 Since all subjects were not restudied at each time interval, results shown in Figure 1,

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Farmer's lung disease: Analysis of 75 cases
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La enfermedad del pulmón de granjero (EPG) es una forma frecuente de neumonitis por hipersensibilidad, posiblemente infradiagnosticada. El objetivo de este estudio es describir las características clínicas, la evolución y los factores que influyen en el pronóstico de los pacientes con EPG.
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A retrospective study that included all patients diagnosed with FLD presenting an environmental exposure risk, a clinic, lung function and a compatible radiology, in which antigen sensitisation was demonstrated and/or a concordant pathology.
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It is unknown if the radiographic fibrosis score predicts mortality in persistent hypersensitivity pneumonitis (HP) and if survival is similar to that observed in idiopathic pulmonary fibrosis (IPF) when adjusting for the extent of radiographic fibrosis.
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Manuscript received July 24; revision accepted November 21.

Reprint requests: Dr. Cormier.; Hopital Laval, 2725 Chemin Ste Foy, Ste Foy, Quebec, Canada G1V 4G5

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Chest

Clinical InvestigationsLong-term Physiologic Outcome after Acute Farmer's Lung

Section snippets

Materials and Methods

Results

Discussion

Am J Med

Lancet

Farmer's lung: a clinical, radiographic, functional and serological correlation of acute and chronic stages

Thorax

Interstitial lung disease

Farmer's lung: an acute granulomatous interstitial pneumonitis occurring in agricultural workers

JAMA

Farmer's lung: a form of pneumoconiosis due to organic dust

Am J Roentgenol

The long term prognosis in farmer's lung

Am Rev Respir Dis

Clinical Investigations
Long-term Physiologic Outcome after Acute Farmer's Lung