Lower respiratory tract diseases

Question 1

Different lower respiratory tract diseases

Answer 1

Found for approximately 10% of the worldwide burden of mortality.

Acute bronchitis

Bronchiolitis

Whooping cough (pertussis)

Pneumonia

Tuberculosis

Question 2

Acute bronchitis

Answer 2

Inflammation of the bronchi. This inflammation causes increased mucus production and other changes.
Most common are acute and chronic bronchitis

RF are people who smoke and have COPD

Causes:
– usually caused by viral infection, usually the same viruses that cause colds and the flu
– 85-95% of cases are virus in healthy adults
– most common viruses- rhinovirus, influenza A and B
– bacteria can cause bronchitis in people with underlying health conditions

Symptoms:
- early symptoms:
— irritating, non-productive cough, together with discomfort behind the sternum
— may be associated with chest tightness, wheezing and shortness of breath

• later symptoms:
  — cough becomes productive, with yellow or green sputum
  — mild fever
  — sore throat
  — runny nose
  — shortness of breath
  — wheeze with occasional crackles

In healthy adults, the disease should improve spontaneously within 4-8 days without them becoming seriously ill
– 85% of patients will improve without specific treatment

– considerable overlap between acute bronchitis and other respiratory infections like asthma and pneumonia

Question 3

Bronchiolitis

Answer 3

Common chest infection that affects babies and children under the age of 2.
Its usually mild and can be treated at home, but it can be serious.

Causes:
– viral infection, usually RSV (respiratory syncytial virus)
—- RSV is very common and spreads easily in coughs and sneezes
—- almost all children have had it by the time they are 2

Symptoms:
- early symptoms (similar to that of a cold):
— sneezing
— runny or blocked nose
— cough
— slightly high temperature of 38 degrees

• may get other symptoms like:
  — tachypnoea
  — finding it difficult to feed or eat
  — noisy breathing
  — become irritable

Symptoms are usually worst between days 3 and 5, and the cough usually gets better in 3 weeks

Question 4

Whooping cough (pertussis)

Answer 4

Bacterial infection of the lungs and breathing tubes

Spread easily through drops and sneezes, very contagious

It spreads very easily

First signs are very difficult to a cold

Can be dangerous

Causes:
– bacterial infection from bacterium bordatella pertussis

Epidemiology:
– uncommon due to vaccinations
– can occur at any age, more serious under the age of 6 months
– 90% of cases occurring before the age of 5

Symptoms:
- after about a week: (symptoms dont appear until then)
– coughing bouts that last for a few minutes and are worse at night
— will make a ‘whoop’ sound in between coughs like a gasp for air (may not occur however)
— may bring up thick mucus which may make you vomit
— may become very red in the face (more common in adults)

Can be dangerous:
- babies under 6 months old have increased chances of:
— dehydration
— breathing difficulties
— pneumonia
— fits (seizures)

3 stages:
– catarrhal, paroxysmal and convalescent

• catarrhal:
  – pt is highly infectious in this stage
  – presents with malaise, faitgue, mucoid rhinorrhea and conjunctivitis
• paroxysmal:
  – coughing bouts
  – whoop sound only seen in young children

Convalescent:
– lasts approximately 2 weeks
– associated with complications like:
— pneumonia, atelectasis, rectal prolapse, inguinal hernia

Whooping cough less serious in older children and adults

May last 4-8 weeks

Question 5

Pneumonia

Answer 5

Inflammation of the substance of the lungs and is usually caused by bacteria
Inflames the air sacs in one or both lungs.
These sacs may fill with fluid or pus (purulent material), causing cough with phlegm or pus, fever, chills, and dyspnoea

Cause:
– usually caused by bacteria
– most common cause overall by pneumococcus.
—- bateria:
—- streptococcus pneumoniae (community acquired pneumonia usually)
—- mycoplasma pneumonia
—- viruses:
—- influenza A virus (usually with a bacterial component)

– 30-50% of cases no organism is identifiable
– in about 20% one or more organisms is present

RF of community acquired pneumonia:
– <16 or >65
– co morbidities
– lifestyle
– other respiratory conditions
– iatrogenic

Other causes:
– Chlamydia psittaci (contact with birds)
– coxiella burnetii (contact with farm animals)
– legionella pneumophila (recent stays in large institutions)
– contact with other patients with pneumonia

Community-acquired pneumonia (most common type of pneumonia):
– streptococcus pneumoniae
– chlamydia pneumoniae
– other bacteria and viruses

Symptoms:
– can vary depending upon the causative agent
– most common symptoms:
—- pyrexia (fever)
—- cough purulent sputum (green)
—- breathlessness
—- fatigue
—- nausea nad vomiting
—- pleuritic chest pain

Older patients:
– may show less symptoms than younger patients and be in a confusional state (recurrent falls)

Severe community-acquired pneumonia:
– confusion
– respiratory rate >30/min
– blood pressure- diastolic <60mmHg
– aged- 65 years

Extrapulmonary features:
– myalgia
– malaise
– headache
– diarrhoea
– vomiting

Precipitating factors for pneumonia:
– underlying lung disease
– smoking
– alcohol abuse
– immunosuppression
– other chronic illnesses

Question 6

Tuberculosis

Answer 6

Bacterial infection that is spread though inhaling tiny droplets from the coughs or sneezes of an infected person.
Mainly affects the lungs, but it can affect any part of the body, including the abdomen, glands, bones and nervous system

Causes:
– 4 main mycobacterial species:
—- mycobacterium tuberculosis
—- mycobacterium bovis
—- mycobacterium africanum
—- mycobacterium microti

Risk factors:
– contact with high risk groups (frequent travel to high risk areas)
– immune deficiency:
—- HIV
—- immunosuppressant medication or corticosteroids
—- vitamin D deficiency
—- diabetes mellitus
—- chronic kidney disease

– genetic susceptibility

Symptoms:
- general symptoms:
– lack of appetite and weight loss
– pyrexia
– night sweats
– malaise

• pulmonary TB (most common):
  – productive cough (occasionally haemoptysis)
  – weight loss
  – fevers
  – sweats
• Lymph node TB (2nd most common):
  – extrathoracic nodes are affected more than intrathoracic and mediastinal

– usually presents as a firm, non-tender enlargement of a cervical or supraclavicular node
—- node becomes necrotic centrally

Different types of TB:
- primary- first infection with one of the mycobacterium TB’s

• latent- immune system contains infection, pt develops cell-mediated immune therapy to the bacteria
• reactivation TB- most cases of TB are due to reactivation of latent infection