Chronic eosinophilic pneumonia

Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun. Eosinophilic pneumonia is a disease in which an eosinophil, a type of white blood cell, accumulates in the lungs. These cells cause disruption of the normal air spaces (alveoli) where oxygen is extracted from the atmosphere. Several different kinds of eosinophilic pneumonia exist and can occur in any age group. The most common symptoms include cough, fever, difficulty breathing, and sweating at night. Eosinophilic pneumonia is diagnosed by a combination of characteristic symptoms, findings on a physical examination by a health provider, and the results of blood tests and X-rays. Prognosis is excellent once most eosinophilic pneumonia is recognized and treatment with corticosteroids is begun. Eosinophilic pneumonia is divided into different categories depending upon whether its cause can be determined or not. Known causes include certain medications or environmental triggers, parasitic infections, and cancer. Eosinophilic pneumonia can also occur when the immune system attacks the lungs, a disease called eosinophilic granulomatosis with polyangiitis. When a cause cannot be found, the eosinophilic pneumonia is termed 'idiopathic'. Idiopathic eosinophilic pneumonia can also be divided into acute and chronic forms, depending on the symptoms a person is experiencing. Most types of eosinophilic pneumonia have similar signs and symptoms. Prominent and nearly universal signs and symptoms include cough, fever, difficulty breathing, and night sweats. Acute eosinophilic pneumonia typically follows a rapid course. Fever and cough may develop only one or two weeks before breathing difficulties progress to the point of respiratory failure requiring mechanical ventilation. Chronic eosinophilic pneumonia usually follows a slower course. Symptoms accumulate over several months and include fever, cough, difficulty breathing, wheezing, and weight loss. Individuals with chronic eosinophilic pneumonia are often misdiagnosed with asthma before the correct diagnosis is made. Eosinophilic pneumonia due to medications or environmental exposures is similar and occurs after an exposure to a known offending agent. Eosinophilic pneumonia due to parasitic infections has a similar prodrome in addition to a host of different symptoms related to the variety of underlying parasites. Eosinophilic pneumonia in the setting of cancer often develops in the context of a known diagnosis of lung cancer, cervical cancer, or other certain types of cancer. Eosinophilic pneumonia can develop in several different ways depending on the underlying cause of the disease. Eosinophils play a central role in defending the body against infection by parasites. Many diseases, such as asthma and eczema, are caused when eosinophils overreact to environmental triggers and release an excess of chemicals, e.g., cytokines and histamine. The common characteristic among different causes of eosinophilic pneumonia is eosinophil overreaction or dysfunction in the lungs. Medications, substance abuse, and environmental exposures may all trigger eosinophil dysfunction. Medications such as nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), nitrofurantoin, phenytoin, L-tryptophan, daptomycin and ampicillin, and drugs of abuse such as inhaled heroin and cocaine may trigger an allergic response which results in eosinophilic pneumonia. Chemicals such as sulfites, aluminum silicate, and cigarette smoke can cause eosinophilic pneumonia when inhaled. A New York City firefighter developed eosinophilic pneumonia after inhalation of dust from the World Trade Center on September 11, 2001. Parasites cause eosinophilic pneumonia in three different ways. Parasites can either invade the lungs, live in the lungs as part of their life cycle, or be spread to the lungs by the bloodstream. Eosinophils then migrate to the lungs in order to fight the parasites, and cause eosinophilic pneumonia when they release there contents. Important parasites that invade the lungs include Paragonimus lung flukes and the tapeworms Echinococcus and Taenia solium. Important parasites which inhabit the lungs as part of their normal life cycle include the worms (helminths) Ascaris lumbricoides, Strongyloides stercoralis and the hookworms Ancylostoma duodenale and Necator americanus. When eosinophilic pneumonia is caused by helminths, it is often called 'Löffler's syndrome'. The final group of parasites cause eosinophilic pneumonia when their eggs are carried into the lungs by the bloodstream. This can include Trichinella spiralis, Strongyloides stercoralis, Ascaris lumbricoides, the hookworms, and the schistosomes.