Pneumonitis is a normal term for inflammation of lung tissue.Chronic inflammation of lung tissue can result in irreversible scarring (pulmonary fibrosis).Pneumonitis is not a definite disease but a sign of an underlying disorder.While pneumonia is technically a form of pneumonitis, most doctors are referring to other causes (hypersensitivity or chemical effect) of lung inflammation when they use the term "pneumonitis".Acute chemical pneumonitis produces swelling of the lung tissue, movement of fluid into the air spaces in the lung and decreased ability to absorb oxygen and remove carbon dioxide.In severe instances, death of patients may occur from hypoxia.Chronic pneumonitis may result from low levels of exposure to the irritant over long periods of time, producing inflammation which may result in fibrosis, leading to reduced gas exchange and stiffening of the lung, and eventually resulting in respiratory failure and death.CausesThe disease can be caused by many known factors such as:1. Breathing in animal dander,2. Exposure to feathers or bird excrement,3. Aspiration inhaling small food particles,4. Sepsis,5. Inhaling chemicals, such as of spores of some species of mushroom or Sodium hydroxide and6. Receiving radiation therapy to the chestCauses of pneumonitis are:1. Pneumonia - . Pneumonitis is normally used for noninfectious causes of lung inflammation.2. Inhalation of foreign matter, normally of stomach contents3. Pertussis (whooping cough)4. Exposure to an inhaled allergen5. Connective tissue diseases6. Adverse reaction to a drug or toxic chemical; many household and industrial chemicals7. Exposure to dangerous levels of chlorine gas8. Inhalation of dangerous substances can happen during smelting, welding or other metalwork9. Medicine: a variety of medicines can cause interstitial pneumonitis10. Radiation therapySymptoms of pneumonitis are:1. Shortness of breath2. Cough3. Fatigue4. Loss of appetite5. Unintentional weight loss6. Cyanosis7. Finger clubbing8. Exercise intoleranceDiagnosisAt the physical examination, the doctor will use a stethoscope to listen carefully to the lungs while the patient breathes.1. Blood tests: FBC may be raised neutrophilia, lymphocytosis, eosinophilia, ESR raised in inflammation2. Blood gases: hypoxemia3. Sputum or culture of lung secretions with bronchoscopy4. Serum activating antibodies against offending antigens for suspected pneumonitisChest X-rayCXR may be normal or show micro-nodular or reticular opacitiesCT scanIt may show:1. Diffuse, patchy ground-glass attenuation and small, poorly defined centrilobular nodules;2. Patchy areas of air-trapping;3. Evidence of pulmonary fibrosis and4. Honeycombing seen in chronic and advanced lung diseaseSpirometer measure lung function to see if it is normalBronchoscopy check brochioles and do lung lavage or obtain samples of cells for testingSurgical lung biopsyTreatmentTreatment of pneumonitis is dependent on the underlying cause and may need medicines such as:1. Systemic corticosteroid therapy, which can improve resolution of pneumonitis.These drugs work by suppressing the immune system, decreasing inflammation in the lungs.2. Antibiotics for infection.3. If the patient has hypersensitivity or chemical pneumonitis, the doctor will advise eradicating exposure to the allergen or chemical irritating to the lungs.4. Oxygen therapy5. Lifestyle and home remediesNo smokingChange of hobbiesChange of workPneumonitis that goes not noticed or not treated can produce irreversible lung damage.TABLE OF CONTENTIntroductionChapter 1 Inflamed Lungs (Pneumonitis)Chapter 2 CausesChapter 3 SymptomsChapter 4 DiagnosisChapter 5 TreatmentChapter 6 PrognosisChapter 7 PneumoniaChapter 8 Chronic Obstructive Lung DiseaseEpilogue