Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a syndrome caused by the repetitive inhalation of antigens from the environment in susceptible or sensitized people. Common antigens include molds, bacteria, bird droppings, bird feathers, agricultural dusts, bioaerosols and chemicals from paints or plastics. People affected by this type of lung inflammation (pneumonitis) are commonly exposed to the antigens by their occupations, hobbies, the environment and animals. The inhaled antigens produce a hypersensitivity immune reaction causing inflammation of the airspaces (alveoli) and small airways (bronchioles) within the lung. Hypersensitivity pneumonitis may eventually lead to interstitial lung disease. Signs and symptoms
Hypersensitivity pneumonitis (HP) can be categorized as acute, subacute, and chronic based on the duration of the illness. Acute
In the acute form of HP dose of antigen exposure tends to be very high but only for a short duration. Symptoms may develop 4–6 hours following heavy exposure to the provoking antigen. Symptoms include fever, chills, malaise, cough, chest tightness, dyspnea, rash, swelling and headache. Symptoms resolve within 12 hours to several days upon cessation of exposure. Subacute
Patients with subacute HP gradually develop a productive cough, dyspnea, fatigue, anorexia, weight loss, and pleurisy. Symptoms are similar to the acute form of the disease, but are less severe and last longer. Findings may be present in patients who have experienced repeated acute attacks. Chronic
In chronic HP, dose of the antigen tends to be low volume but for a longer duration. Patients often lack a history of acute episodes.
Lycoperdonosis is a respiratory disease caused by the inhalation of large amounts of spores from mature puffballs. It is classified as a hypersensitivity pneumonitis (also called extrinsic allergic alveolitis)—an inflammation of the alveoli within the lung caused by hypersensitivity to inhaled natural dusts. It is one of several types of hypersensitivity pneumonitis caused by different agents that have similar clinical features. Typical progression of the disease includes symptoms of a cold hours after spore inhalation, followed by nausea, rapid pulse, crepitant rales (a sound like that made by rubbing hairs between the fingers, heard at the end of inhalation), and dyspnea. Chest radiographs reveal the presence of lung nodules. The early symptoms presented in combination with pulmonary abnormalities apparent on chest radiographs may lead to misdiagnosis of the disease as tuberculosis, histiocytosis, or pneumonia caused by Pneumocystis carinii. Lycoperdonosis is generally treated with corticosteroids, which decrease the inflammatory response; these are sometimes given in conjunction with antimicrobials.The disease was first described in the medical literature in 1967 by R.D. Strand and colleagues in the New England Journal of Medicine. In 1976, a 4-year-old was reported developing the disease in Norway after purposely inhaling a large quantity of Lycoperdon spores to stop a nosebleed. Lycoperdon species are sometimes used in folk medicine in the belief that their spores have haemostatic properties. A 1997 case report discussed several instances of teenagers inhaling the spores. In one severe case, the individual inhaled enough spores so as to be able to blow them out of his mouth.