Farmer's Lung Follow-up
- Author: Laurianne G Wild, MD, FAAAAI, FACAAI; Chief Editor: Zab Mosenifar, MD, FACP, FCCP more...
Further Outpatient Care
Outpatient care includes the following:
- 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.
Further Inpatient Care
Inpatient care includes the following:
- 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
Complete avoidance of the antigen is indicated. Consider the following:
- 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.
Complications of farmer's lung include the following:
- Cor pulmonale
- Hypoxemic respiratory failure
- Pulmonary fibrosis
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. Consider the following:
- 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 include recurrent acute episodes, allergy to mites, organic dust, and fungal elements, and smoking, which promotes deterioration of lung function in patients diagnosed with farmer's lung.
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 patient education information, see Bronchoscopy.
Ramazzini B, Wright WC, eds. De Morbis Artificium [Diseases of Workers]. New York, NY: Hafner Publishing; 1964.
Barrera C, Valot B, Rognon B, Zaugg C, Monod M, Millon L. Draft genome sequence of the principal etiological agent of farmer's lung disease, Saccharopolyspora rectivirgula. Genome Announc. 2014 Dec 18. 2(6):[Medline]. [Full Text].
Lehrer SB, Turer E, Weill H, Salvaggio JE. Elimination of bagassosis in Louisiana paper manufacturing plant workers. Clin Allergy. 1978 Jan. 8(1):15-20. [Medline].
Liu S, Chen D, Fu S, et al. Prevalence and risk factors for farmer's lung in greenhouse farmers: an epidemiological study of 5,880 farmers from Northeast China. Cell Biochem Biophys. 2015 Mar. 71(2):1051-7. [Medline].
Barrera C, Millon L, Rognon B, et al. Immunoreactive proteins of Saccharopolyspora rectivirgula for farmer's lung serodiagnosis. Proteomics Clin Appl. 2014 Dec. 8(11-12):971-81. [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].
Deschenes D, Provencher S, Cormier Y. Farmer's lung-induced hypersensitivity pneumonitis complicated by shock. Respir Care. 2012 Mar. 57(3):464-6. [Medline].
Bellanger AP, Reboux G, Botterel F, et al. New evidence of the involvement of Lichtheimia corymbifera in farmer's lung disease. Med Mycol. 2010 Nov. 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. 2007 Jul. 82(7):812-6. [Medline].
Malmberg P, Rask-Andersen A, Palmgren U, Hoglund S, Kolmodin-Hedman B, Stalenheim G. Exposure to microorganisms, febrile and airway-obstructive symptoms, immune status and lung function of Swedish farmers. Scand J Work Environ Health. 1985 Aug. 11(4):287-93. [Medline].
Kokkarinen J, Tukiainen H, Terho EO. Mortality due to farmer's lung in Finland. Chest. 1994 Aug. 106(2):509-12. [Medline].
Arya A, Roychoudhury K, Bredin CP. Farmer's lung is now in decline. Ir Med J. 2006 Jul-Aug. 99(7):203-5. [Medline].
Cormier Y, Belanger J. The fluctuant nature of precipitating antibodies in dairy farmers. Thorax. 1989 Jun. 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. 1987 Feb. 91(2):274-5. [Medline].
Monkare S, Ikonen M, Haahtela T. Radiologic findings in farmer's lung. Prognosis and correlation to lung function. Chest. 1985 Apr. 87(4):460-6. [Medline].
Cormier Y, Brown M, Worthy S, Racine G, Muller NL. High-resolution computed tomographic characteristics in acute farmer's lung and in its follow-up. Eur Respir J. 2000 Jul. 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. 1968 Feb. 97(2):223-31. [Medline].
Ohtsuka Y, Munakata M, Tanimura K, et al. Smoking promotes insidious and chronic farmer's lung disease, and deteriorates the clinical outcome. Intern Med. 1995 Oct. 34(10):966-71. [Medline].
Thorshauge H, Fallesen I, Ostergaard PA. Farmer's lung in infants and small children. Allergy. 1989 Feb. 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. 1997 Dec. 112(6):1459-65. [Medline].
Takahashi T, Munakata M, Ohtsuka Y, et al. Serum KL-6 concentrations in dairy farmers. Chest. 2000 Aug. 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. 1997 Jan. 111(1):245-8. [Medline].
Imai K, Ashitani J, Imazu Y, et al. [Farmer's lung cases of a farmer and his son with high BAL fluid beta-D glucan levels]. Nihon Kokyuki Gakkai Zasshi. 2004 Dec. 42(12):1024-9. [Medline].
Ando M, Suga M. Hypersensitivity pneumonitis. Curr Opin Pulm Med. 1997 Sep. 3(5):391-5. [Medline].
Bouchard S, Morin F, Bedard 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. 1995 Sep. 152(3):997-1002. [Medline].
Cormier Y, Belanger J. Long-term physiologic outcome after acute farmer's lung. Chest. 1985 Jun. 87(6):796-800. [Medline].
Emanuel DA, Kryda MJ. Farmer's lung disease. Clin Rev Allergy. 1983 Dec. 1(4):509-32. [Medline].
Fink JN, Zacharisen MC. Hypersensitivity pneumonitis. Middleton E Jr, Reed CE, Ellis EF, Adkinson NF Jr, Yunginger JW, Busse WW, eds. Allergy Principles and Practice. 5th ed. St. Louis, Mo: Mosby; 1998. 994-1004.
Fink JN. Hypersensitivity pneumonitis. Clin Chest Med. 1992 Jun. 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. 1993 Nov. 159(5):570-8. [Medline].
Kline JN, Schwartz DA. Agricultural dust-induced lung disease. 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. 1993 Apr. 147(4):793-6. [Medline].
Lalancette M, Carrier G, Laviolette M, et al. Farmer's lung. Long-term outcome and lack of predictive value of bronchoalveolar lavage fibrosing factors. Am Rev Respir Dis. 1993 Jul. 148(1):216-21. [Medline].
Myers ML. Health problems and disease patterns in agriculture. 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. 2001 Nov. 108(5):661-70. [Medline].
Patterson R, Greenberger PA, Castile RG, et al. Diagnostic problems in hypersensitivity lung disease. Allergy Proc. 1989 Mar-Apr. 10(2):141-7. [Medline].
Salvaggio JE. Extrinsic allergic alveolitis (hypersensitivity pneumonitis): past, present and future. Clin Exp Allergy. 1997 May. 27 Suppl 1:18-25. [Medline].
Schuyler M, Cormier Y. The diagnosis of hypersensitivity pneumonitis. Chest. 1997 Mar. 111(3):534-6. [Medline].
Schuyler M, Gott K, Edwards B. Experimental hypersensitivity pneumonitis: cellular requirements. Clin Exp Immunol. 1996 Jul. 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].
Rognon B, Reboux G, Roussel S, et al. Western blotting as a tool for the serodiagnosis of farmer's lung disease: validation with Lichtheimia corymbifera protein extracts. J Med Microbiol. 2015 Apr. 64(Pt 4):359-68. [Medline].