Respiratory diseases Flashcards
Common cold (coryza) etiology, features and management
- Etiology: viruses - rhinoviruses, coronaviruses, RSV
- Features:
- Clear or mucopurulent nasal discharge
- Nasal blockage
- Management: self-limiting, anti analgesics
- Cough may persist for up to 4 weeks
Pharyngitis: etiology, features and management
- Etiology: mostly viral infection - adenoviruses, enteroviruses, rhinoviruses. Group A beta-hemolytic streptococcus (older children). EBV (tonsillitis)
- Features: pharynx and soft palate are inflamed, local lymphadenopathy. Tonsillitis - inflammation of the tonsils with purulent exudate
- Management: Penicillin V for 10 days
When given Amoxicillin for pharyngitis, child develop widespread maculopapular rash. Why?
Infection with EBV (mononucleosis)
Etiology, features and management of scarlet fever
- Etiology: Group A streptococcus
- Features:
- Fever precedes headache and tonsillitis by 2-3 days.
- ‘Sandpaper-like’ maculopapular rash with flushed cheeks and perioral sparing
- White and coated tongue, may be sore or swollen
- Only childhood exanthema caused by a bacterium
- Management: Penicillin V.
Complications of Group A beta-hemolytic streptococcus pharyngitis?
- Acute glomerulonephritis
- Rheumatic fever’
Pathogens in acute otitis media
- Viruses:
- RSV
- Rhinovirus
- Bacteria:
- Pneumococcus
- Nontypeable Haemophilus influenza
- Moraxella catarrhalis
Treatment for acute otitis media
- Usually resolves spontaneously
- If child remains unwell after 2-3 days: Amoxicillin
Differential Dx of acute stridor (upper airway obstruction)
- Most common: Viral laryngotracheobronchitis = ‘Croup’
- Rare: epiglottitis, bacterial tracheitis, foreign body, angioedema, trauma, retropharyngeal abscess
Pathogens in Croup
- Most common: Parainfluenza
- Other: Rhinovirus, RSV, influenza
Typical age and features of Croupe
- Occurs between 6 months - 6 years, peak at 2 years of age
- Features:
- Coryza (cold symptoms)
- Fever
- Hoarseness (inflammation of vocal cords)
- Barking cough, like a sea lion (tracheal edema and collapse)
- Harsh stridor
- Variable degree of difficulty breathing with chest retraction
- Symptoms often starts and are worse at night
First-line treatment for Croupe
- Oral dexamethasone, Oral prednisolone, or neubilized steroids (budesonide)
- For severe obstruction: neubilized adrenaline with oxygen by face mask
Pathogen in epiglottitis
H. influenza type B (99% reduction after immunization)
Clinical features of epiglottitis
Onset very acute
- High fever, very ill, toxic-looking child
- An intensely painful throat, prevents child from speaking or swallowing
- Saliva drools down the chin
- Soft inspiratory stridor
- Rapidly increasing respiratory difficulty over hours
- Child sitting immobile, upright, with an open mouth
- Minimal or no cough
Pathogen of bronchiolitis
Most common RSV (80% of cases)
Others are parainfluenza virus, rhinovirus, adenovirus, influenza virus, human metapneumovirus
Clinical findings in bronchiolitis
- Croyza (cold symptoms)
- Dry wheezy cough
- Tachypnea and tachycardia
- Subcostal and intercostal recession
- Hyperinflation of the chest
- Fine end-inspiratory crackles
- High-pitched wheezes - prolonged expiration
When to admit child with bronchiolitis to hospital?
- Apnea
- Persistent SpO2 <90% on room air
- Inadequate oral fluid intake
- Severe respiratory distress - grunting, marked chest recession, RR >70 breaths/minute
Causes of acute respiratory distress in an infant
- Bronchiolitis
- Viral episodic wheeze
- Pneumonia
- HF
- Foreign body
- Anaphylaxis
- Pneumothorax, pleural effusion
- Metabolic acidosis
- Severe anemia
What are the three patterns of wheezing?
- Viral episodic wheezing - only in response to viral infection
- Multiple trigger wheeze - in response to multiple triggers and which is more likely to develop into asthma over time
- Asthma
Pathophysiology of asthma
Bronchial inflammation: * Edema * Excessive mucus production * Infiltration with cells (eosinophils, mast cells, neutrophils, lymphocytes) Bronchial hyperresponsiveness: * Exaggerated "twitchiness" to inhaled stimuli Airway narrowing: * Reversible airflow obstruction
Clinical features in asthma
Should be suspected in a child with:
- Wheezing in more than one occasion
- More common in children with a personal or family history of atopy
Features:
- Symptoms worse at night and in the early morgning
- Nonviral triggers
- Interval symptoms, i.e. symptoms between acute exacerbations
- Positive response to asthma therapy
4 major symptoms in asthma
- Wheeze
- Dry cough
- Breathlessness
- Chest tightness
What does Harrison’s sulci indicate?
- Depressions at the base of the thorax.
- Associated with chronic obstructive airways disease such as asthma, from chronic increased work of breathing
How much must the FEV1 improve after bronchodilators, to be diagnosed as asthma?
Improvement of 12% or more –> bronchodilator reversibility
Short-acting beta2-agonists
- Called relievers
- Salbutamol, Terbutaline
- Rapid onset of action - maximum effect after 10-15 min
- Effective for 2-4 hours
- Used “as required” for increased symptoms
Long-acting beta2-agonist (LABAs)
- Salmeterol or Formoterol
- Effective for 12 hours
- Should not be used without an inhaled corticosteroid
First-line treatment in asthma
Relievers:
- Short-acting beta2-agonist (Salbutamole)
Preventers:
- Inhaled corticosteroids (Budesonide, Fluticasone)
- Add-on therapy:
* >5 y.o. - LABA (Salmeterol)
* <5 y.o. - Oral leukotriene receptor antagonist/LTRA (Montelukast)
Management in asthma attacks
- High-dose inhaled bronchodilators, steroids and oxygen. (goal SpO2 >92%)
- Addition of neutralized Ipratropium
- Short course of oral prednisolone
- To children who fails to respond adequately to inhaled therapy:
* Magnesium sulphate I.V.
* Aminophylline I.V.
* Salbutamol I.V.
What type of pneumonia can cause wheezing?
Atypical pneumonia caused by:
- Mycoplasma
- Chlamydia
- Adenovirs
Clinical features of whooping cough (Pertussis)
Catarrhal phase (1 week):
- Coryza
Paroxysmal phase (up to 3 months):
- Paroxysmal or spasmodic cough followed by a characteristic inspiratory whoop
Convalescent phase (may persist for many months):
- Symptoms gradually decrease
- Spasm often worse at night, may culminate in vomiting
- During paroxysm - child goes red or blue in face, mucous flows from the nose and mouth.
- Woop may be absent in infant - then apnea
- Epistaxis and subconjunctival hemorrhages
Most common causes for a persistent cough
- Most common caused by series of respiratory tract infections
- Other: Pertussis, RSV, Mycoplasma
Most common pathogens causing pneumonia
Newborn: * Group B streptococcus * Gram-negative enterococci (E. coli) and bacilli Infants and young children: * RSV - most common * Streptococcus pneumonia * H. influenza (marked reduction after immunization) * Bordetella pertussis * Chlamydia trachomatis * Staph. aureus Children >5 y.o. * Mycoplasma pneumonia * Streptococcus pneumonia * Chlamydia pneumonia All ages: * Mycobacterium tuberculosis
Most common symptoms of pneumonia
- Fever
- Cough
- Tachypnea
Other: Lethargy, poor feeding, an ‘unwell’ child
Bacterial infection: Localized chest, abdominal or neck pain –> pleural irritation
Clinical findings in pneumonia
- Tachypnea - most sensitive clinical sign
- Nasal flaring
- Chest indrawing
- End-inspiratory coarse crackles
Causes of generalized bronchiectasis
- Cystic fibrosis
- Primary ciliary dyskinesia
- Immunodeficiency
- Chronic aspiration
Causes of localized bronchiectasis
- Previous severe pneumonia
- Congenital lung abnormality
- Obstruction by a foreign body
What is defect in CF?
CF transmembrane conductance regulator (CFTR)
- A cyclic AMP-dependent chloride channel
On which chromosome is the gene for CFTR found?
Chromosome 7
What is the most frequent mutation in CF?
F508 –> Class II mutation
* Incorrect folding - cannot traffic to membrane
Pathophysiology of CF
Abnormal ion transport across epithelial cells
- Airways:
- Reduction in airway surface liquid layer
- Impaired ciliary function
- Retention of mucopurulent secretions
- Dysregulation of inflammation and defence against infection
- Intestine:
- Thick viscid meconium - meconium ileus
- Pancreas:
- Blocked pancreatic ducts - pancreatic enzyme deficiency and malabsorption
- Sweat glands:
- Excessive concentrations of sodium and chloride in sweat
Which factor do you look for in CF screening?
Immunoreactive trypsinogen (IRT) is raised in newborns with CF
Clinical features in CF
Newborn: - Meconium ileus Infant: - Jaundice - Growth faltering - Recurrent chest infections - Malabsorption, steatorrhea Young child: - Bronchiectasis - Rectal prolapse - Nasal polyps - Sinusitis Older child: - Allergic bronchopulmonary aspergillosis - DM - Cirrhosis and portal HTN - Distal intestinal obstruction - Pneumothorax or recurrent hemoptysis - Sterility in males
What is the main cause of death in CF?
95 % die of respiratory failure
How to diagnose CF?
Sweat test:
- Increased chloride in sweat - 60-125 mmol/L (normal = 10-40 mmol/L)
Which pathogens causes lung infections in CF?
- Staph. aureus
- H. influenza
- Pseudomonas
- Burkholderia cepacia
Cause of ciliary dyskinesia
Congenital abnormality in the structure or function of cilia ling the respiratory tract.
Lead to impaired mucociliary clearance
Primary ciliary dyskinesia, symptoms
- Recurrent productive cough
- Purulent nasal discharge
- Chronic ear infections
What i Kartagener syndrome?
Situs inversus - major organs are in mirror position of normal
