Respiratory System

• Pharyngitis

  • Inflammation or infection of the pharynx is caused mostly by cold and flu viruses.
  • If bacterial, usually caused by Streptococcus, the throat may contain pus
  • Symptoms/signs: a sore and itchy throat, cough, body ache, low-grade grade fever, and running nose.
• Laryngitis

  • Inflammation of the larynx caused mostly by cold or flu virus
  • If bacterial, it is usually due to H.influenza and diptheriae, but rarely.
  • GERD (acid reflux) and smoking can also cause laryngitis.
  • Symptoms/signs: hoarseness, weak voice or loss of voice, tickling, sore throat, and dry cough.
• Epiglottitis

  • Inflammation/infection of the epiglottis caused mostly by H.influenzae
  • Can be fatal if the airway is blocked. especially in children.
  • Rare due to the Hib vaccine.

  (fatal if children get it_developing children)
• Sinusitis

  • Inflammation/infection of the sinus due to allergen, virus, or polyps.
  • This leads to mucus build-up in the sinuses.
  • Symptoms/Signs: facial pressure, stuffy running nose, congestions, bad breath, fatigue, and dental pain.
• Tonsilitis

  • Inflammation/infection of the tonsils is caused by cold viruses but if bacterial, mostly due to streptococcus.
  • If the airway is blocked(in children), it is life-threatening, especially in young children.
  • Doctors will remove the tonsils to widen the airway.
• Diphtheria

  • Infection of the respiratory tract caused by Corynebacterium diphtheriae
  • Diphtheria toxin kills cells by including heart and nerve cells
  • Signs/Symptoms: a sore throat, fever, cough, swollen lymph nodes (bull neck) and breathing difficulty
  • One sign is the presence of a pseudomembrane (tissue death) in the pharynx and tonsil
  • Prevention via DTaP vaccine.
• Otitis externa (swimmer’s ear)

  • Inflammation/infection of the outer ear and ear canal
  • Signs/Symptoms: pain and swelling
  • Caused by exposure of cut skin to skin microbes
• Otitis media

  • Inflammation/infection of the middle ear caused usually by Streptococcus pneumonia, especially in children
  • Usually, it starts as an upper respiratory infection that spreads to the Eustachian tube and then to the middle ear.
  • Symptoms/Signs: flu-like, ear pain, headache, tinnitus, and vertigo.
• Common cold

  • Infection is usually by the rhinovirus and coronavirus
  • Typically occurs in fall and spring, but can appear year-round whereas the flu primarily occurs in cold/winter months
  • Symptoms are sneezing, mucus, malaise(불안감), and sore throat
  • Usually, no fever nor muscle aches which are typically seen in flu.
• Parainfluenza

  • Infection by human parainfluenza viruses which affects mainly children and has cold-like symptoms can be signs.
  • Can be serious in children and people with poor immunity if leads to:
  • Croup (high-pitched cough due to larynx inflammation, especially in young children)
  • Stridor (high-pitched breathing)
• Whooping Cough (Pertussis “violent cough”)

  • Infection is caused by Bordetella pertussis and is transmitted via respiratory droplets.
  • Toxins kill ciliated cells in the trachea, leading to mucus build up and blockage of the airways.
  • Infants and children straining to breath produce a characteristic “whooping” sound,
  • FYI, the severity of the cough can cause rib fractures, hemorrhage, and convulsions.
  • Vaccination with DTaP is key
• Pneumonia

  • Infection/inflammation of the lungs can be caused by a variety of pathogens.
  • General symptoms/signs are:
  • fever
  • cough with mucus
  • shortness of breath and chest pain
  • rapid breathing and fatigue
  • confusion or delirium due to lack of oxygen, especially in older people
• Lobar pneumonia

  • Bacterial infection caused mostly by Strep pneumoniaie a.k.a. pneumococcus
  • Infection is usually confined to a specific lobe of the lungs and causes the lungs to be filled with mucus/fluid and less elastic.
  • Generally occurs in young healthy adults
• Bronchial pneumonia

  • Affects multiple lobes of the lungs
  • Usually occurred as a secondary infection
  • Occurs primarily in children under 2 and older people at the extreme end of life or those with immune disorders and other illnesses (i.e. cancer, heart failure)
  • Also known as “old man’s friend”.
• Legionnaire’s disease

  • Caused by Legionella pneumophila
  • Mode of transmission is ingestion/inhalation of contaminated water via water aerosol (AC, shower head, vaporizer, hot tubs)
  • Signs/symptoms: fever, chills, headache, diarrhea, and fluid in the lungs
  • Middle-aged smokers and the immunocompromised are most at risk with fatality as high as 50% in susceptible people.
  • Prevention is key(chlorinated water, periodic cleaning), but can be treated with antibiotics.
• Tuberculosis (a.k.a. Consumption)

  • Caused by Mycobacterium tuberculosis.
  • Transmitted via respiratory droplets and about 2-3 billion are infected and 3 million die each year
  • In the lungs, bacteria is engulfed (완전히 에워싸다) by macrophage, but are not killed. Instead, the entombed bacteria is imprisoned in a hard tissue called tubercles(make your lung elastic). Tubercles negatively impeded respiration.
  • Signs/symptoms include fever, chills, night sweats, loss of appetite, fatigue, severe cough with bloody sputum(가래), death.
• Psittacosis/Ornithosis

  • Lung infection is caused by Chlamydophila psittaci and is associated with birds(parakeets, parrots, etc.)
  • Most cases are mild, but in immunocompromised or ailing individuals, it can lead to high fevers, joint pain, pneumonia, and death.
  • FYI, sequelae of ornithosis include endocarditis, hepatitis, and neurologic complications.
• Q fever (Query fever)

  • Highly infectious lung caused by Coxiella burnetti. It is transmitted via inhalation or ingestion of domestic animals body fluid(urine, feces, milk) and pets (cat, sheep, cow)
  • Symptoms/signs: usually mild to flu-like but can be serious if leads to infection of vital organs (lungs, heart, brain, liver)
  • Women who are infected during pregnancy may be at risk for miscarriage, stillbirth, pre-term delivery, or low infant birth weight.
  • FYI, due to its contagiousness, pathogenicity, and infection dose of 10 cells, it is a potential bioweapon.
• Severe Acute Respiratory Syndrome (SARS)

  • Infection by coronavirus causes severe flu-like symptoms.
  • FYI, the mortality rate about 9~15% compared to influenza which has a death rate of 1~6%.
  • Note, that the SARS death rate is 50% in older people.
• Hantavirus(transmitted from mice) Pulmonary Syndrome

  • transmitted via inhalation of rodent(설치류) feces (ex. deer mice)
  • Causes severe flu-like symptoms with a high fatality rate of 38%.
• Coccidioidomycosis (San Joaquin Valley Fever)

  • Caused by inhalation of spores of Coccidioides immitis (fungus) found in Southwest US
  • Like in tuberculosis, the fungus is phagocytized by macrophages but is not killed by the macrophage.
  • Susceptible(민감한) individuals develop pneumonia, but the fungus can disseminate(퍼뜨리다) to the brain.
  • Immunocompromised individuals are most at risk as well as Filipino-, African-, Native-, and Asian-American
• Histoplasmosis

  • Infection by Histoplasma capsulatum which is endemic or central and eastern US and causes pneumonia and encephalitis in susceptible people.
  • Those most at risk are those with poor or weakened immunity.
• Paragonimus (lung flukes)

  • Caused by the consumption of undercooked or raw crustaceans (shrimp, crab, crayfish) and other hosts of the fluke
  • Male and female fluke migrate from the gut(intestine) to the lungs where they mate and eggs are produced
  • The eggs are coughed up and are swallowed into the GI tract where they are excreted with feces.
  • Symptoms/signs: chronic coughing, bloody sputum, malnutrition, and difficult breathing.