Pneumonia is a form of acute respiratory infection that affects the lungs. The lungs are made up of small sacs called alveoli, which fill with air when a healthy person breathes. When an individual has pneumonia, the alveoli are filled with pus and fluid, which makes breathing painful and limits oxygen intake.
Pneumonia is the single largest infectious cause of death in children worldwide. Pneumonia killed 808 694 children under the age of 5 in 2017, accounting for 15% of all deaths of children under five years old. Pneumonia affects children and families everywhere, but is most prevalent in South Asia and sub-Saharan Africa. Children can be protected from pneumonia, it can be prevented with simple interventions, and treated with low-cost, low-tech medication and care.
The most common symptom of pneumonitis is shortness of breath, which may be accompanied by a dry cough. If pneumonitis is undetected or left untreated, you may gradually develop chronic pneumonitis, which can result in scarring (fibrosis) in the lungs.
Signs and symptoms of chronic pneumonitis include:
• Shortness of breath
• Chest pain when you breathe or cough
• Loss of appetite
• Nausea, vomiting or diarrhea
• Unintentional weight loss
Pneumonitis occurs when an irritating substance causes the tiny air sacs (alveoli) in your lungs to become inflamed. This inflammation makes it difficult for oxygen to pass through the alveoli into the bloodstream.
Many irritants, ranging from airborne molds to chemotherapy drugs, have been linked to pneumonitis. But for most people, the specific substance causing the inflammation is never identified.
• Drugs. A variety of drugs can cause pneumonitis, including some antibiotics, several types of chemotherapy drugs and medications that keep your heartbeat regular. An overdose of aspirin can cause pneumonitis.
• Molds and bacteria. Repeated exposure to some molds and bacteria can cause the lungs to become inflamed. Specific varieties of mold-related pneumonitis have received nicknames, such as “farmer’s lung” or “hot tub lung.”
• Birds. Exposure to feathers or bird excrement is a common cause of pneumonitis.
• Radiation treatments. Some people who undergo radiation therapy to the chest, such as for breast or lung cancer, may develop pneumonitis. Pneumonitis also can occur after whole-body radiation therapy, which is needed to prepare a person for a bone marrow transplant.
Some occupations and hobbies carry higher risks of pneumonitis, including:
• Farming. Many types of farming operations expose workers to aerosolized mists and pesticides. Inhaling airborne particles from moldy hay is one of the most common causes of occupational pneumonitis. Mold particles also can be inhaled during harvests of grain and hay.
• Bird handling. Poultry workers and people who breed or keep pigeons are often exposed to droppings, feathers and other materials that can cause pneumonitis.
• Hot tubs and humidifiers. Moldy conditions in hot tubs can trigger pneumonitis because the bubbling action makes a mist that can be inhaled. Home humidifiers are another common reservoir for mold.
Pneumonitis that goes unnoticed or untreated can cause irreversible lung damage.
In normal lungs, the air sacs stretch and relax with each breath. Chronic inflammation of the thin tissue lining each air sac causes scarring and makes the sacs less flexible. They become stiff like a dried sponge. This is called pulmonary fibrosis. In severe cases, pulmonary fibrosis can cause right heart failure, respiratory failure and death.
Even with treatment, some people with pneumonia, especially those in high-risk groups, may experience complications, including:
• Bacteria in the bloodstream (bacteremia). Bacteria that enter the bloodstream from your lungs can spread the infection to other organs, potentially causing organ failure.
• Difficulty breathing. If your pneumonia is severe or you have chronic underlying lung diseases, you may have trouble breathing in enough oxygen. You may need to be hospitalized and use a breathing machine (ventilator) while your lung heals.
• Fluid accumulation around the lungs (pleural effusion). Pneumonia may cause fluid to build up in the thin space between layers of tissue that line the lungs and chest cavity (pleura). If the fluid becomes infected, you may need to have it drained through a chest tube or removed with surgery.
• Lung abscess. An abscess occurs if pus forms in a cavity in the lung. An abscess is usually treated with antibiotics. Sometimes, surgery or drainage with a long needle or tube placed into the abscess is needed to remove the pus.
To help prevent pneumonia:
• Get vaccinated. Vaccines are available to prevent some types of pneumonia and the flu. Talk with your doctor about getting these shots. The vaccination guidelines have changed over time so make sure to review your vaccination status with your doctor even if you recall previously receiving a pneumonia vaccine.
• Make sure children get vaccinated. Doctors recommend a different pneumonia vaccine for children younger than age 2 and for children ages 2 to 5 years who are at particular risk of pneumococcal disease. Children who attend a group child care center should also get the vaccine. Doctors also recommend flu shots for children older than 6 months.
• Practice good hygiene. To protect yourself against respiratory infections that sometimes lead to pneumonia, wash your hands regularly or use an alcohol-based hand sanitizer.
• Don’t smoke. Smoking damages your lungs’ natural defenses against respiratory infections.
• Keep your immune system strong. Get enough sleep, exercise regularly and eat a healthy diet.
www.mayoclinic.org ( Pneumonia)