J60-J70: Lung diseases due to external agents

J67: Hypersensitivity pneumonitis due to organic dust

Hypersensitivity pneumonitis, also known as allergic alveolitis, is a group of lung diseases caused by an allergic reaction to certain types of dust. These could include those from mold, fungus, animal proteins, and certain chemicals, often found in places like farms, or in certain industries or hobbies. The condition usually develops after frequent, long-term exposure to these substances, not immediately after a single contact. Symptoms include fever, cough, and shortness of breath, often appearing 4-6 hours after exposure. Over time, if the exposure continues, these conditions may lead to chronic lung inflammation and scarring, called fibrosis. This could potentially affect the function of the lungs, causing progressive breathlessness. These conditions can also change pattern and severity based on the specific type of dust causing the reaction.