Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Farmer's lung pathophysiology
Introduction
Overview
Overview
The pathogenesis of the Farmer’s lung disease is type 3 or type 4 hypersensitivity reaction.
Pathophysiology
Pathophysiology
Pathogenesis:
Hypersensitivity reaction because of the many immunologic phenomenon present and antibodies of organism invasion into tissues.
Acute-
- Type 3 hypersensitivity
- When moldy hay antigens complex with antibodies, to bind complements and attract neutrophils, causing inflammation by release of their toxic enzymes and radicals.[1]
Chronic-
- Type 4 hypersensitivity
- mononuclear cell inflammation and granuloma.
Unifying hypothesis-
Sensitized pulmonary alveolar macrophages activated by antigen attract neutrophils and also modulate T cell activity leading to appearance of mononuclear cells and granuloma.[2]
Associated Conditions
Associated Conditions
There are no associated conditions.
Gross Pathology
Gross Pathology
Acute phase-
- Pulmonary alveolar wall and interstitial accumulation of neutrophils, mononuclear cells and edema.
- Obstructive bronchiolitis and capillary inflammation is present.
Late phase-
- mononuclear cell predominant
- presence of noncaseating granuloma