Clinical Infections - Respiratory Flashcards
Pharyngitis and Tonsillar Pharyngitis definition
- Inflammation of the back of the throat (pharynx), resulting sore throat & fever
- Common cause is viruses and bacteria
Acute tonsillar pharyngitis =
- symmetrically inflamed tonsils and pharynx (+ systemic symptoms = severe infection)
Management of Pharyngitis and Tonsillar Pharyngitis
- Centor Criteria = likelihood of sore throat being due to bacterial infection – likely if score is 3 or 4 (unlikely if less)
- oral analgesics, more severe = antibiotics
Otitis Externa (OE) definition
- Inflammation of the external ear canal presenting with a combination of: otalgia (ear ache), pruritus (severe itching of skin) and non-mucoid ear discharge
Acute OE
- 90% cases bacterial
- Ear swab or pus sample
- Treatment = remove precipitating factors, pus and debris, analgesia then antimicrobials
Malignant (Necrotising) External Otitis
- Affects skull base - life threatening
- Immunocompromised
- Severe pain, otorrhea, cranial nerve palsies
- Management = prompt referral to ENT
Chronic OE
- White keratin debris may fill ear canal and skin may thicken = blockage
- Aetiology = contact dermatitis
- Treat underlying cause
Otitis Media (OM) definition
- Middle ear inflammation with build-up of fluid
- Common in children
Complicated OM =
- Severe pain, perforated eardrum +/- discharge, bilateral infection, mastoiditis
- Infection of mastoid bone/air cells
Management = CT scan, analgesia, IV antibiotics +/- mastoidectomy
Treatment of Uncomplicated OM
- Management = swab any pus, treat symptoms, amoxicillin
Pinna Cellulitis
Aetiology = Trauma, surgery/burns, infective agents
Complication = perichondritis (inflammation of connective tissue of the pinna)
- Management = swab of the area and blood cultures before antibiotics
Pneumonia definition
- Infection affecting the most distal airways and alveoli with formation of inflammatory exudate
- Bronchopneumonia and lobar pneumonia
Community Acquired Pneumonia (CAP)
- Typical = S.pneumoniae, Enterobacteriaceae
- Spread person to person
- 50-70, midwinter-spring
- CURB65 = assessment of disease
- if CURB65 >2, do cultures
Hospital Acquired Pneumonia (HAP)
- Develops >48 hours after admission
- Most common organism = pseudomonas
Ventilator Acquired Pneumonia
- A subgroup of HAP; develops >48 hours after ET intubation and ventilation
Aspiration pneumonia
- Pneumonia resulting from the abnormal entry of fluids into the lower respiratory tract – patient usually has impaired swallowing
- Most common organism = anaerobes
Mycoplasma pneumoniae =
children and young adults, present with cough
Atypical pneumonia management
- Stabilise – ABC, then prompt empirical therapy
Legionella pneumophilia
- Colonises water piping systems, present with high fevers, rigors, cough: dry initially but becomes productive, vomiting, diarrhoea,
Chlamydophilia pneumoniae
- Causes mild pneumonia or bronchitis in adolescents & young adults. Incidence highest in the elderly
Chlamydophilia psittaci
Associated with exposure to birds. Consider in those with pneumonia, splenomegaly & history of bird exposure
Viral LRTI - Influenza
- Flu - Influenza A/B
- dry couch, sore throat 2-3 weeks
- Complication = viral pneumonia + secondary bacterial pneumonia
- Diagnosis = viral antigen detection in respiratory samples using PCR
Viral LRTI - VZV
- significant morbidity & mortality in adults with VZV
- Onset 1-6 days after the rash has appeared with symptoms of progressive tachypnoea, dyspnoea, and dry cough
- chest X-ray typically reveals diffuse bilateral infiltrates
- supportive & prompt administration of IV antibiotics
Viral LRTI - Rhinovirus
- Common cold
- Can trigger exacerbations of asthma
- Tests = PCR on NPA/throat swab
- Treatment is supportive
Viral LRTI - CMV
- CMV pneumonia is a complication of CMV
- Seen in immunocompromised
- Tests = CXR, broncho-alveolar lavage & viral load PCR
- Treatment = supportive, anti-virals
LRTI with Bronchiectasis
- Lungs are more vulnerable to infection
- Suspect bronchiectasis if recurrent infections and if sputum is green
- Treatment = effective clearance of sputum, underlying cause treated
LRTI with Cystic Fibrosis
- S.aureus in childhood and Pseudomonas aeruginosa
- Burkholderia cepacia complex = very resistant
- Prolonged antibiotic courses e.g. 3-4 weeks
Vaccinations that prevent LRTI’s
- Pneumococcal (S. pneumoniae) = chronic disease
- Influenza = annual in vulnerable groups
Aspergillosis
- Aspergillosis = opportunistic – seen in immunocompromised and those with respiratory pathology.
- Presentation = allergic reaction, lung/other organ infection
Allergic Bronchopulmonary Aspergillosis (ABPA)
- Epidemiology = background of atopy, asthma and CF
- Symptoms = worsening asthma and lung function, central bronchiectasis
- Diagnostic features = high total IgE, specific IgE/IgG to aspergillus
- Treatment = supportive care, corticosteroids and antifungal therapy
Pulmonary aspergilloma
- Mobile mass of aspergillus in a pre-existing lung cavity
- Symptoms = cough, haemoptysis, weight loss, wheeze & clubbing
- Treatment = surgical resection and antifungals
PCP (pneumocystis jiroveci pneumonia)
- An opportunistic fungal infection
- Resistant to number of antifungals
- Diagnosis = organisms in induced sputum, PCR to detect P. jiroveci DNA
- Treatment = supportive care, steroids and antimicrobials. Some e.g. HIV+ = prophylaxis
Nocardia Asteroides
- Acquired through inhalation of nocardia
- Seen mostly in immunosuppressed and those with respiratory pathology
- Lung abscesses can form
- Diagnosis = organisms in sputum, broncho-alveolar lavage or biopsy
- Treatment = supportive care and antibiotics
Mycobacterium tuberculosis
- Most frequent cause of infectious death
- Inhalation of infected resp. droplets which lodge and multiply in alveoli
Symptoms of pulmonary TB
- Chronic productive cough, haemoptysis, weight loss, fever, night sweats
What happens to a TB infection
- Depending on the host’s immune response the infection will either become quiescent (inactive) or progress and/or disseminate (affect other organs) - highest risk of this/reactivation at the extremes of age and in the immunocompromised
Diagnosis and treatment of TB
- Diagnosis = supportive radiology + detection of acid-fast bacilli
- Detection = PCR based
- Treatment = combined chemotherapy
- Prevention = BCG (Bacillus Calmette-Guérin vaccine)
