pulmonary disorders
Hypersensitivity Pneumonitis
Symptoms and Signs of Hypersensitivity Pneumonitis
Symptoms and signs tend to depend on whether onset is Acute Chronic Subacute Only a small proportion of exposed people develop symptoms and in most cases only after weeks to months of exposure and sensitization. Acute disease occurs in previously sensitized people with acute high-level antigen exposure and manifests as fever, chills, cough, bilateral vice-like chest tightness (as can occur in asthma), and dyspnea 4 to 8 hours after exposure. Anorexia, nausea, and vomiting may also be present. Physical examination shows tachypnea, diffuse fine-to-medium inspiratory crackles, and, in almost all cases, absence of wheezing. Chronic disease occurs in people with long-term low-level antigen exposure (such as owners of birds) and manifests as onset over months to years of exertional dyspnea, productive cough, fatigue, and weight loss. There are few physical findings; clubbing uncommonly occurs, and fever is absent. In advanced cases, pulmonary fibrosis causes symptoms and signs of Cor Pulmonale , Subacute disease falls between the acute and chronic forms and manifests either as cough, dyspnea, fatigue, and anorexia that develops over days to weeks or as acute symptoms superimposed on chronic ones. 