Inflammation and thickening of the walls of the alveoli (tiny air sacs) in the lungs. Alveolitis reduces the elasticity, and therefore the efficiency, of the lungs. It is most commonly due to an allergic reaction to inhaled dust of animal or plant origin, as in farmer’s lung, bagassosis, and pigeon fancier’s lung (due to particles from bird droppings).
Fibrosing alveolitis is an autoimmune disorder. In some cases, it occurs with other autoimmune disorders such as rheumatoid arthritis or systemic lupus erythematosus. Radiation alveolitis is caused by irradiation of the lungs and may occur as a rare complication of radiotherapy for lung or breast cancer.
Alveolitis usually causes a dry cough and breathing difficulty on exertion. A chest X-ray, blood tests, pulmonary function tests, or a lung biopsy may be needed to diagnose alveolitis.
For most types of alveolitis, a short course of corticosteroid drugs relieves symptoms, but for fibrosing alveolitis these may need to be taken indefinitely. If the cause of allergic alveolitis is recognized and avoided before lung damage occurs, the effects are not permanent. In fibrosing alveolitis, damage progresses despite treatment, causing increasing breathing difficulty and, sometimes, respiratory failure.
In?ammation of the alveoli (see ALVEOLUS) of the lungs caused by an allergic reaction. When the in?ammation is caused by infection it is called PNEUMONIA, and when by a chemical or physical agent it is called pneumonitis. It may be associated with systemic sclerosis or RHEUMATOID ARTHRITIS.
Extrinsic allergic alveolitis is the condition induced by the lungs becoming allergic (see ALLERGY) to various factors or substances. It includes BAGASSOSIS, FARMER’S LUNG and BUDGERIGAR-FANCIER’S LUNG, and is characterised by the onset of shortness of breath, tightness of the chest, cough and fever. The onset may be sudden or gradual. Treatment consists of removal of the affected individual from the o?ending material to which he or she has become allergic. CORTICOSTEROIDS give temporary relief.
Fibrosing alveolitis In this disease there is di?use FIBROSIS of the walls of the alveoli of the lungs. This causes loss of lung volume with both forced expiratory volume and vital capacity affected, but the ratio between them remaining normal. The patient complains of cough and progressive DYSPNOEA. Typically the patient will be cyanosed (blue – see CYANOSIS), clubbed (see CLUBBING), and have crackles in the mid- and lower-lung ?elds. Blood gases will reveal HYPOXIA and, in early disease, hypocapnia (de?ciency of carbon dioxide in the blood due to hyperventilation). There is an association with RHEUMATOID ARTHRITIS (about one-eighth of cases), systemic lupus erythematosus (see under LUPUS), and systemic SCLEROSIS. Certain drugs – for example, bleomycin, busulphan and hexamethonium – may also cause this condition, as may high concentrations of oxygen, and inhalation of CADMIUM fumes.
n. inflammation of an *alveolus or alveoli. Chronic inflammation of the walls of the alveoli of the lungs is usually caused by inhaled organic dusts (extrinsic allergic alveolitis; see bird-fancier’s lung; farmer’s lung) but may occur spontaneously (cryptogenic fibrosing alveolitis, CFA). CFA is now usually called *idiopathic pulmonary fibrosis because the fibrosis seems to precede the alveolitis. It may be associated with connective tissue diseases, such as rheumatoid arthritis or systemic sclerosis.
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