T Soumagne1, B Degano2, J C Dalphin3. 1. Service de pneumologie, hôpital Jean-Minjoz, 2, boulevard Fleming, 25030 Besancon cedex, France. Electronic address: thibaud_soumagne@live.fr. 2. Service d'explorations fonctionnelles de la respiration, de l'exercice et de la dyspnée, hôpital Jean-Minjoz, 2, boulevard Fleming, 25030 Besancon cedex, France. 3. Service de pneumologie, hôpital Jean-Minjoz, 2, boulevard Fleming, 25030 Besancon cedex, France.
Abstract
INTRODUCTION: Farmer's lung (FL) is the most common type of hypersensitivity pneumonitis (HP), with an estimated prevalence of between 0.5 and 1.5% in dairy farmers. In chronic FL, fibrotic sequelae are widely described in the literature although our experience and occasional epidemiological studies emphasize an increased risk of developing emphysema in these patients. CASE REPORT: We report a case of FL in a 37-year-old patient with typical clinical features (exertional dyspnoea, lymphocytic alveolitis and computed tomography appearances) together with proven allergen exposure. This patient developed early pulmonary emphysema probably due to intermittent massive exposure to antigens and to bacterial and fungal micro-organisms. CONCLUSION: The current classification of HP differentiates acute, subacute and chronic forms but does not take account of the role of the mode of exposure and the evolution of the disease. The prognosis and evolution of HP seem to be dependent on the type and pattern of exposure. A new classification with two clusters has been suggested: in type 1, massive and intermittent exposure, as in FL, may lead to emphysema with chronic airflow obstruction and, in type 2, chronic exposure to a low level, as in bird fanciers, may lead to fibrosis with a restrictive pattern.
INTRODUCTION:Farmer's lung (FL) is the most common type of hypersensitivitypneumonitis (HP), with an estimated prevalence of between 0.5 and 1.5% in dairy farmers. In chronic FL, fibrotic sequelae are widely described in the literature although our experience and occasional epidemiological studies emphasize an increased risk of developing emphysema in these patients. CASE REPORT: We report a case of FL in a 37-year-old patient with typical clinical features (exertional dyspnoea, lymphocytic alveolitis and computed tomography appearances) together with proven allergen exposure. This patient developed early pulmonary emphysema probably due to intermittent massive exposure to antigens and to bacterial and fungal micro-organisms. CONCLUSION: The current classification of HP differentiates acute, subacute and chronic forms but does not take account of the role of the mode of exposure and the evolution of the disease. The prognosis and evolution of HP seem to be dependent on the type and pattern of exposure. A new classification with two clusters has been suggested: in type 1, massive and intermittent exposure, as in FL, may lead to emphysema with chronic airflow obstruction and, in type 2, chronic exposure to a low level, as in bird fanciers, may lead to fibrosis with a restrictive pattern.
Authors: Thibaud Soumagne; Marie-Laure Chardon; Gaël Dournes; Lucie Laurent; Bruno Degano; François Laurent; Jean Charles Dalphin Journal: PLoS One Date: 2017-06-14 Impact factor: 3.240