Alveolitis, extrinsic allergic
Alveolitis, extrinsic allergic Definition
Extrinsic allergic alveolitis (EAA), also known as hypersensitivity pneumonitis, is an inflammation of the alveoli found in the lung. This condition is caused by hypersensitivity to various types of inhaled organic dusts. People with this disease are usually exposed to dust from their hobbies or occupations. Several types of extrinsic allergic alveolitis exist based on the provoking antigen. These include Bird-Breeder's Lung (avian proteins), Farmer's Lung (molds), Bagassosis (moldy bagasse or sugarcane), Malt Worker's Lung (moldy barley), Humidifier Lung (by mist of standing water). Mushroom Worker's Lung (mushroom compost), Compost Lung (compost), Peat Moss Worker's Lung (peat moss), Suberosis (moldy cork dust), Japanese Summer-Type HP (damp wood and mats) and Cheese-Washer's Lung (cheese casings). Other types of EAA include Hot Tub Lung, Mollusc Shell HP, Metalworking Fluids HP, Isocyanate HP, TMA HP, Beryllium and Wine-grower's Lung. The most common of all EAA are Bird-Breeder's Lung and Farmer's Lung, affecting 8 to 850 people in 100,000 persons each year for farmers alone and 6,000 to 21,000 people in 100,000 persons for pigeon breeders yearly.
Alveolitis, extrinsic allergic Diagnosis
Diagnosis of EAA is based on clinical tests and the patient's symptom history after exposure to the allergen. Tests include x-ray, lung function exam and blood tests.
Alveolitis, extrinsic allergic Symptoms and Signs
Symptoms of extrinsic allergic alveolitis are categorized as acute, sub-acute and chronic based on the duration of the condition. In acute EAA, symptoms occur 4 to 6 hours after heavy exposure to the antigen. These symptoms include cough, chills, fever, malaise, dyspnea, headache and chest tightness. However, the symptoms usually resolve within 12 hours. In sub-acute EAA, patients develop fatigue, pleurisy, anorexia, dyspnea, weight loss and productive cough. While symptoms of sub-acute EAA are similar to the acute form, the symptoms of this type of condition last longer. In Chronic EAA patients, symptoms include progressive dypnea, weight loss, fatigue and dangerous onset of cough. Over 50% of patients experience clubbing, while others develop respiratory distress, inspiratory crackles and tachypnea. Removing exposure to antigen will only result in partial improvement.
Alveolitis, extrinsic allergic Treatment
The most effective treatment to EAA is to avoid the provoking allergen since chronic exposure could cause permanent damage or even death. Prednisolone and corticosteroids may also help relieve symptoms. However, these drugs could also produce unwanted side effects.