Farmer's Lung Follow-up
- Author: Laurianne G Wild, MD, FAAAAI; Chief Editor: Zab Mosenifar, MD more...
Further Inpatient Care
- Systemic corticosteroids
- Serum precipitins
- Flexible bronchoscopy to exclude other etiologies
- Transbronchial biopsy may be of limited benefit in patients with acute farmer's lung.
- Open lung biopsy may be indicated to confirm the diagnosis if other diagnostic criteria are not met.
Further Outpatient Care
- Routine spirometry with lung volumes and diffusion capacity
- Arterial PO2 and arterial-alveolar gradient: Recommend exercise (6-min walk or by ergometer) if the room air PO2 level is normal.
- Monitor chest radiographs and consider high-resolution CT scans of the chest to seek resolution of infiltrates or presence of ground-glass opacities that may indicate a need for further treatment with corticosteroids and/or continued insult to the lungs by antigen exposure.
Deterrence/Prevention
- Complete avoidance of the antigen is indicated.
- Protective devices (eg, masks) may reduce the amount of antigen; however, again, complete avoidance is recommended.
- Maintaining humidity at less than 60% may discourage microbial growth.
- Keeping hay on farms dry and well protected may discourage growth of bacteria and molds. However, salting of hay, a traditional empirical practice used to prevent molding in hay, does not significantly decrease the amount of actinomycetes, the organisms most commonly involved in farmer's lung disease. Salting of hay may provide a false sense of security that the farmer is protected from developing farmer's lung; this false notion should be dispelled.[15]
Complications
- Cor pulmonale
- Hypoxemic respiratory failure
- Pulmonary fibrosis
- Death
Prognosis
- The long-term prognosis of farmer's lung varies and depends on the extent of fibrosis and the amount of irreversible damage to the lung parenchyma.[16]
- In some patients, the disease may progress even after the antigen exposure has been eliminated.
- If the diagnosis of farmer's lung is confirmed before irreversible changes have developed, most patients recover with minimal functional abnormalities and few become disabled.
- In the acute stages, restriction with decreased static compliance and diffusing capacity that reverses over several weeks (with antigen avoidance) may occur.
- In subacute disease, bronchiolitis and granuloma formation might be slower to resolve even with corticosteroid therapy.
- Individuals with a ground-glass appearance on high-resolution CT scans of the chest have higher response rates to systemic corticosteroids.
- Patients with honeycombing or pulmonary fibrosis may have less than a 20% response to corticosteroids and a mortality rate greater than 90% at 5 years after diagnosis.
- Predictors of long-term decline in farmer's lung
- Recurrent acute episodes
- Allergy to mites, organic dust, and fungal elements
- Smoking, which promotes deterioration of lung function in patients diagnosed with farmer's lung[17]
Patient Education
- Environmental control and complete avoidance of the antigen should be the goal.
- Complete avoidance of the environment or farm may be required to ensure prevention of chronic disease and survival.
- Many farmers have thought that salting the hay can prevent the growth of molds in the hay. However, salting does not prevent the growth of molds. The use of salt does not significantly decrease the amount of Saccharopolyspora rectivirgula (the actinomycetes most commonly involved in farmer's lung disease), or Absidia corymbifera, Eurotium amstelodami, and Wallemia sebi, 3 molds responsible for farmer's lung disease in Europe. Therefore, palatable hay is not safe hay.
- For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article Bronchoscopy.
Ramazzini B, Wright WC, ed. De Morbis Artificium [Diseases of Workers]. New York, NY: Hafner Publishing; 1964.
Lehrer SB, Turer E, Weill H, Salvaggio JE. Elimination of bagassosis in Louisiana paper manufacturing plant workers. Clin Allergy. Jan 1978;8(1):15-20. [Medline].
Ashitani J, Kyoraku Y, Yanagi S, Matsumoto N, Nakazato M. Elevated levels of beta-D-glucan in bronchoalveolar lavage fluid in patients with farmer's lung in Miyazaki, Japan. Respiration. 2008;75(2):182-8. [Medline].
Deschênes D, Provencher S, Cormier Y. Farmer's Lung-Induced Hypersensitivity Pneumonitis Complicated by Shock. Respir Care. Oct 12 2011;[Medline].
Bellanger AP, Reboux G, Botterel F, Candido C, Roussel S, Rognon B, et al. New evidence of the involvement of Lichtheimia corymbifera in farmer's lung disease. Med Mycol. Nov 2010;48(7):981-7. [Medline].
Hanak V, Golbin JM, Ryu JH. Causes and presenting features in 85 consecutive patients with hypersensitivity pneumonitis. Mayo Clin Proc. Jul 2007;82(7):812-6. [Medline].
Depierre A, Dalphin JC, Pernet D, Dubiez A, Faucompré C, Breton JL. Epidemiological study of farmer's lung in five districts of the French Doubs province. Thorax. Jun 1988;43(6):429-35. [Medline].
Malmberg P, Rask-Andersen A, Palmgren U, Höglund S, Kolmodin-Hedman B, Stålenheim G. Exposure to microorganisms, febrile and airway-obstructive symptoms, immune status and lung function of Swedish farmers. Scand J Work Environ Health. Aug 1985;11(4):287-93. [Medline].
Kokkarinen J, Tukiainen H, Terho EO. Mortality due to farmer's lung in Finland. Chest. Aug 1994;106(2):509-12. [Medline].
Arya A, Roychoudhury K, Bredin CP. Farmer's lung is now in decline. Ir Med J. Jul-Aug 2006;99(7):203-5. [Medline].
Cormier Y, Bélanger J. The fluctuant nature of precipitating antibodies in dairy farmers. Thorax. Jun 1989;44(6):469-73. [Medline].
Arshad M, Braun SR, Sunderrajan EV. Severe hypoxemia in farmer's lung disease with normal findings on chest roentgenogram. Chest. Feb 1987;91(2):274-5. [Medline].
Mönkäre S, Ikonen M, Haahtela T. Radiologic findings in farmer's lung. Prognosis and correlation to lung function. Chest. Apr 1985;87(4):460-6. [Medline].
Cormier Y, Brown M, Worthy S, Racine G, Müller NL. High-resolution computed tomographic characteristics in acute farmer's lung and in its follow-up. Eur Respir J. Jul 2000;16(1):56-60. [Medline].
Roussel S, Reboux G, Dalphin JC, Laplante JJ, Piarroux R. Evaluation of salting as a hay preservative against farmer's lung disease agents. Ann Agric Environ Med. 2005;12(2):217-21. [Medline].
Barbee RA, Callies Q, Dickie HA, Rankin J. The long-term prognosis in farmer's lung. Am Rev Respir Dis. Feb 1968;97(2):223-31. [Medline].
Ohtsuka Y, Munakata M, Tanimura K, Ukita H, Kusaka H, Masaki Y, et al. Smoking promotes insidious and chronic farmer's lung disease, and deteriorates the clinical outcome. Intern Med. Oct 1995;34(10):966-71. [Medline].
Thorshauge H, Fallesen I, Ostergaard PA. Farmer's lung in infants and small children. Allergy. Feb 1989;44(2):152-5. [Medline].
Lacasse Y, Fraser RS, Fournier M, Cormier Y. Diagnostic accuracy of transbronchial biopsy in acute farmer's lung disease. Chest. Dec 1997;112(6):1459-65. [Medline].
Takahashi T, Munakata M, Ohtsuka Y, Satoh-Kamachi A, Sato R, Homma Y, et al. Serum KL-6 concentrations in dairy farmers. Chest. Aug 2000;118(2):445-50. [Medline].
Nakagawa-Yoshida K, Ando M, Etches RI, Dosman JA. Fatal cases of farmer's lung in a Canadian family. Probable new antigens, Penicillium brevicompactum and P olivicolor. Chest. Jan 1997;111(1):245-8. [Medline].
Imai K, Ashitani J, Imazu Y, Yanagi S, Sano A, Tokojima M, et al. [Farmer's lung cases of a farmer and his son with high BAL fluid beta-D glucan levels]. Nihon Kokyuki Gakkai Zasshi. Dec 2004;42(12):1024-9. [Medline].
Ando M, Suga M. Hypersensitivity pneumonitis. Curr Opin Pulm Med. Sep 1997;3(5):391-5. [Medline].
Bouchard S, Morin F, Bédard G, Gauthier J, Paradis J, Cormier Y. Farmer's lung and variables related to the decision to quit farming. Am J Respir Crit Care Med. Sep 1995;152(3):997-1002. [Medline].
Cormier Y, Bélanger J. Long-term physiologic outcome after acute farmer's lung. Chest. Jun 1985;87(6):796-800. [Medline].
Emanuel DA, Kryda MJ. Farmer's lung disease. Clin Rev Allergy. Dec 1983;1(4):509-32. [Medline].
Fink JN. Hypersensitivity pneumonitis. In: Allergy Principles and Practice. 5th ed. St. Louis, Mo: Mosby; 1998:994-1004.
Fink JN. Hypersensitivity pneumonitis. Clin Chest Med. Jun 1992;13(2):303-9. [Medline].
Fraser RG, Pare JA. Diagnosis of Diseases of the Chest. 3rd ed. Philadelphia, Pa: WB Saunders; 1989:1273-90.
Gay J, Donham KJ, Leonard S. Iowa Agricultural Health and Safety Service Project. Am J Ind Med. 1990;18(4):385-9. [Medline].
Kaltreider HB. Hypersensitivity pneumonitis. West J Med. Nov 1993;159(5):570-8. [Medline].
Kline JN, Schwartz DA. Agricultural dust-induced lung disease. In: Rom WN, ed. Environmental Occupational Medicine. Philadelphia, Pa: Lippincott Raven; 1998:565-71.
Kokkarinen JI, Tukiainen HO, Terho EO. Recovery of pulmonary function in farmer's lung. A five-year follow-up study. Am Rev Respir Dis. Apr 1993;147(4):793-6. [Medline].
Lalancette M, Carrier G, Laviolette M, Ferland S, Rodrique J, Bégin R, et al. Farmer's lung. Long-term outcome and lack of predictive value of bronchoalveolar lavage fibrosing factors. Am Rev Respir Dis. Jul 1993;148(1):216-21. [Medline].
Myers ML. Health problems and disease patterns in agriculture. In: Encyclopedia of Occupational Health Safety. Geneva, Switzerland: International Labour Office; 1997.
Patel AM, Ryu JH, Reed CE. Hypersensitivity pneumonitis: current concepts and future questions. J Allergy Clin Immunol. Nov 2001;108(5):661-70. [Medline].
Patterson R, Greenberger PA, Castile RG, et al. Diagnostic problems in hypersensitivity lung disease. Allergy Proc. Mar-Apr 1989;10(2):141-7. [Medline].
Salvaggio JE. Extrinsic allergic alveolitis (hypersensitivity pneumonitis): past, present and future. Clin Exp Allergy. May 1997;27 Suppl 1:18-25. [Medline].
Schuyler M, Cormier Y. The diagnosis of hypersensitivity pneumonitis. Chest. Mar 1997;111(3):534-6. [Medline].
Schuyler M, Gott K, Edwards B. Experimental hypersensitivity pneumonitis: cellular requirements. Clin Exp Immunol. Jul 1996;105(1):169-75. [Medline].
Wiatr E, Radzikowska E, Pawlowski J. [Pulmonary fibrosis in young patients with hypersensitivity pneumonitis]. Pneumonol Alergol Pol. 2004;72(3-4):111-6. [Medline].
Wild LG. Hypersensitivity pneumonitis: A childhood disease?. Pediatr Asth Allergy. 2000;14:57-75.
Wild LG, Lopez M. Hypersensitivity pneumonitis: a comprehensive review. J Investig Allergol Clin Immunol. 2001;11(1):3-15. [Medline].

